81406402 has 32 divisors (see below), whose sum is σ = 155965824. Its totient is φ = 30940800.

The previous prime is 81406343. The next prime is 81406417. The reversal of 81406402 is 20460418.

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, 133 + ... + 12760.

It is an arithmetic number, because the mean of its divisors is an integer number (4873932).

Almost surely, 2^81406402 is an apocalyptic number.

81406402 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

81406402 is a deficient number, since it is larger than the sum of its proper divisors (74559422).

81406402 is a wasteful number, since it uses less digits than its factorization.

81406402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12954.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 81406402 is about 9022.5496396529. The cubic root of 81406402 is about 433.3972853674.

The spelling of 81406402 in words is "eighty-one million, four hundred six thousand, four hundred two".