81616510 has 16 divisors (see below), whose sum is σ = 148211856. Its totient is φ = 32357248.

The previous prime is 81616501. The next prime is 81616543. The reversal of 81616510 is 1561618.

It is a super-2 number, since 2×81616510² = 13322509409160200, which 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 7 ways as a sum of consecutive naturals, for example, 34984 + ... + 37243.

It is an arithmetic number, because the mean of its divisors is an integer number (9263241).

Almost surely, 2^81616510 is an apocalyptic number.

81616510 is a deficient number, since it is larger than the sum of its proper divisors (66595346).

81616510 is a wasteful number, since it uses less digits than its factorization.

81616510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72347.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 81616510 is about 9034.1856301495. The cubic root of 81616510 is about 433.7698277609.

The spelling of 81616510 in words is "eighty-one million, six hundred sixteen thousand, five hundred ten".