8161997429520 has 240 divisors, whose sum is σ = 31476411720000. Its totient is φ = 1874525690880.

The previous prime is 8161997429483. The next prime is 8161997429549. The reversal of 8161997429520 is 259247991618.

8161997429520 is a `hidden beast` number, since 8 + 1 + 6 + 19 + 9 + 74 + 29 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 26969395 + ... + 27270354.

It is an arithmetic number, because the mean of its divisors is an integer number (131151715500).

Almost surely, 2^{8161997429520} is an apocalyptic number.

8161997429520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8161997429520 is an abundant number, since it is smaller than the sum of its proper divisors (23314414290480).

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

8161997429520 is a wasteful number, since it uses less digits than its factorization.

8161997429520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54239798 (or 54239789 counting only the distinct ones).

The product of its (nonzero) digits is 19595520, while the sum is 63.

The spelling of 8161997429520 in words is "eight trillion, one hundred sixty-one billion, nine hundred ninety-seven million, four hundred twenty-nine thousand, five hundred twenty".