81915120510 has 32 divisors (see below), whose sum is σ = 197418885120. Its totient is φ = 21752632608.

The previous prime is 81915120509. The next prime is 81915120577. The reversal of 81915120510 is 1502151918.

It is a happy number.

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, 5705182 + ... + 5719521.

It is an arithmetic number, because the mean of its divisors is an integer number (6169340160).

Almost surely, 2^81915120510 is an apocalyptic number.

81915120510 is an abundant number, since it is smaller than the sum of its proper divisors (115503764610).

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

81915120510 is a wasteful number, since it uses less digits than its factorization.

81915120510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11424952.

The product of its (nonzero) digits is 3600, while the sum is 33.

The spelling of 81915120510 in words is "eighty-one billion, nine hundred fifteen million, one hundred twenty thousand, five hundred ten".