81236920415670 has 32 divisors (see below), whose sum is σ = 216631787775840. Its totient is φ = 21663178777440.

The previous prime is 81236920415659. The next prime is 81236920415689. The reversal of 81236920415670 is 7651402963218.

It is a happy number.

81236920415670 is a `hidden beast` number, since 8 + 1 + 2 + 36 + 9 + 2 + 0 + 41 + 567 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 150438741241 + ... + 150438741780.

It is an arithmetic number, because the mean of its divisors is an integer number (6769743367995).

It is a 1-persistent number, because it is pandigital, but 2⋅81236920415670 = 162473840831340 is not.

Almost surely, 2^{81236920415670} is an apocalyptic number.

81236920415670 is an abundant number, since it is smaller than the sum of its proper divisors (135394867360170).

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

81236920415670 is a wasteful number, since it uses less digits than its factorization.

81236920415670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300877483037 (or 300877483031 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 81236920415670 in words is "eighty-one trillion, two hundred thirty-six billion, nine hundred twenty million, four hundred fifteen thousand, six hundred seventy".