81261478460 has 48 divisors (see below), whose sum is σ = 171923744160. Its totient is φ = 32262485760.

The previous prime is 81261478427. The next prime is 81261478489. The reversal of 81261478460 is 6487416218.

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, 1915802 + ... + 1957758.

It is an arithmetic number, because the mean of its divisors is an integer number (3581744670).

Almost surely, 2^81261478460 is an apocalyptic number.

It is an amenable number.

81261478460 is an abundant number, since it is smaller than the sum of its proper divisors (90662265700).

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

81261478460 is a wasteful number, since it uses less digits than its factorization.

81261478460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42686 (or 42684 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 47.

The spelling of 81261478460 in words is "eighty-one billion, two hundred sixty-one million, four hundred seventy-eight thousand, four hundred sixty".