81210426 has 16 divisors (see below), whose sum is σ = 177186528. Its totient is φ = 24609200.

The previous prime is 81210413. The next prime is 81210431. The reversal of 81210426 is 62401218.

It is a super-2 number, since 2×81210426² = 13190266582202952, which contains 22 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 81210396 and 81210405.

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, 615165 + ... + 615296.

It is an arithmetic number, because the mean of its divisors is an integer number (11074158).

Almost surely, 2^81210426 is an apocalyptic number.

81210426 is an abundant number, since it is smaller than the sum of its proper divisors (95976102).

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

81210426 is a wasteful number, since it uses less digits than its factorization.

81210426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1230477.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 81210426 is about 9011.6827507408. The cubic root of 81210426 is about 433.0492221813.

The spelling of 81210426 in words is "eighty-one million, two hundred ten thousand, four hundred twenty-six".