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1981801 = 2238887
BaseRepresentation
bin111100011110101101001
310201200112001
413203311221
51001404201
6110251001
722562563
oct7436551
93650461
101981801
111133a58
127b6a61
13545083
14398333
15292301
hex1e3d69

1981801 has 4 divisors (see below), whose sum is σ = 1990912. Its totient is φ = 1972692.

The previous prime is 1981787. The next prime is 1981813. The reversal of 1981801 is 1081891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1981801 - 219 = 1457513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1981801.

It is not an unprimeable number, because it can be changed into a prime (1981891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4221 + ... + 4666.

It is an arithmetic number, because the mean of its divisors is an integer number (497728).

21981801 is an apocalyptic number.

It is an amenable number.

1981801 is a deficient number, since it is larger than the sum of its proper divisors (9111).

1981801 is an equidigital number, since it uses as much as digits as its factorization.

1981801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9110.

The product of its (nonzero) digits is 576, while the sum is 28.

The square root of 1981801 is about 1407.7645399711. The cubic root of 1981801 is about 125.6087849008.

The spelling of 1981801 in words is "one million, nine hundred eighty-one thousand, eight hundred one".

Divisors: 1 223 8887 1981801