81477756904870 has 16 divisors (see below), whose sum is σ = 146838164099040. Its totient is φ = 32551502390784.

The previous prime is 81477756904793. The next prime is 81477756904897. The reversal of 81477756904870 is 7840965777418.

It is a junction number, because it is equal to n+sod(n) for n = 81477756904793 and 81477756904802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4950037755 + ... + 4950054214.

It is an arithmetic number, because the mean of its divisors is an integer number (9177385256190).

Almost surely, 2^{81477756904870} is an apocalyptic number.

81477756904870 is a deficient number, since it is larger than the sum of its proper divisors (65360407194170).

81477756904870 is a wasteful number, since it uses less digits than its factorization.

81477756904870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9900092799.

The product of its (nonzero) digits is 663828480, while the sum is 73.

The spelling of 81477756904870 in words is "eighty-one trillion, four hundred seventy-seven billion, seven hundred fifty-six million, nine hundred four thousand, eight hundred seventy".