81510574072 has 16 divisors (see below), whose sum is σ = 152838306000. Its totient is φ = 40753692480.

The previous prime is 81510574039. The next prime is 81510574081. The reversal of 81510574072 is 27047501518.

It is a super-2 number, since 2×81510574072² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33997 + ... + 405187.

It is an arithmetic number, because the mean of its divisors is an integer number (9552394125).

Almost surely, 2^81510574072 is an apocalyptic number.

It is an amenable number.

81510574072 is a deficient number, since it is larger than the sum of its proper divisors (71327731928).

81510574072 is a wasteful number, since it uses less digits than its factorization.

81510574072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398646 (or 398642 counting only the distinct ones).

The product of its (nonzero) digits is 78400, while the sum is 40.

The spelling of 81510574072 in words is "eighty-one billion, five hundred ten million, five hundred seventy-four thousand, seventy-two".