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1991730195 = 3357213192353
BaseRepresentation
bin111011010110111…
…0110010000010011
312010210210101012000
41312231312100103
513034340331240
6525345405043
7100233266400
oct16655662023
95123711160
101991730195
11932309414
12477039783
132598401a0
1414c7452a7
15b9ccc430
hex76b76413

1991730195 has 384 divisors, whose sum is σ = 4964198400. Its totient is φ = 747242496.

The previous prime is 1991730187. The next prime is 1991730229. The reversal of 1991730195 is 5910371991.

It is a happy number.

It is not a de Polignac number, because 1991730195 - 23 = 1991730187 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1991730195.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 37579789 + ... + 37579841.

It is an arithmetic number, because the mean of its divisors is an integer number (12927600).

Almost surely, 21991730195 is an apocalyptic number.

1991730195 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1991730195 is an abundant number, since it is smaller than the sum of its proper divisors (2972468205).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1991730195 is a wasteful number, since it uses less digits than its factorization.

1991730195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 76545, while the sum is 45.

The square root of 1991730195 is about 44628.8045437025. The cubic root of 1991730195 is about 1258.1821006598.

The spelling of 1991730195 in words is "one billion, nine hundred ninety-one million, seven hundred thirty thousand, one hundred ninety-five".