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87790081 = 190146181
BaseRepresentation
bin1010011101110…
…01001000000001
320010012012100111
411032321020001
5134433240311
612413351321
72114126521
oct516711001
9203165314
1087790081
1145611a95
1225498541
131525a0c2
14b933681
157a91d21
hex53b9201

87790081 has 4 divisors (see below), whose sum is σ = 87838164. Its totient is φ = 87742000.

The previous prime is 87790069. The next prime is 87790121. The reversal of 87790081 is 18009778.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18009778 = 29004889.

It can be written as a sum of positive squares in 2 ways, for example, as 36180225 + 51609856 = 6015^2 + 7184^2 .

It is a cyclic number.

It is not a de Polignac number, because 87790081 - 25 = 87790049 is a prime.

It is a super-2 number, since 2×877900812 = 15414196643973122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87790181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21190 + ... + 24991.

It is an arithmetic number, because the mean of its divisors is an integer number (21959541).

Almost surely, 287790081 is an apocalyptic number.

It is an amenable number.

87790081 is a deficient number, since it is larger than the sum of its proper divisors (48083).

87790081 is a wasteful number, since it uses less digits than its factorization.

87790081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48082.

The product of its (nonzero) digits is 28224, while the sum is 40.

The square root of 87790081 is about 9369.6361188682. The cubic root of 87790081 is about 444.4420579710.

The spelling of 87790081 in words is "eighty-seven million, seven hundred ninety thousand, eighty-one".

Divisors: 1 1901 46181 87790081