81912435 has 16 divisors (see below), whose sum is σ = 142974720. Its totient is φ = 39715040.

The previous prime is 81912427. The next prime is 81912449. The reversal of 81912435 is 53421918.

It is not a de Polignac number, because 81912435 - 2³ = 81912427 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 81912396 and 81912405.

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, 248055 + ... + 248384.

It is an arithmetic number, because the mean of its divisors is an integer number (8935920).

Almost surely, 2^81912435 is an apocalyptic number.

81912435 is a deficient number, since it is larger than the sum of its proper divisors (61062285).

81912435 is a wasteful number, since it uses less digits than its factorization.

81912435 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496458.

The product of its digits is 8640, while the sum is 33.

The square root of 81912435 is about 9050.5488783830. The cubic root of 81912435 is about 434.2934493834.

The spelling of 81912435 in words is "eighty-one million, nine hundred twelve thousand, four hundred thirty-five".