81400008 has 16 divisors (see below), whose sum is σ = 203500080. Its totient is φ = 27133328.

The previous prime is 81400003. The next prime is 81400021. The reversal of 81400008 is 80000418.

It is a super-2 number, since 2×81400008² = 13251922604800128, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81400003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1695810 + ... + 1695857.

It is an arithmetic number, because the mean of its divisors is an integer number (12718755).

Almost surely, 2^81400008 is an apocalyptic number.

It is an amenable number.

81400008 is an abundant number, since it is smaller than the sum of its proper divisors (122100072).

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

81400008 is a wasteful number, since it uses less digits than its factorization.

81400008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3391676 (or 3391672 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 81400008 is about 9022.1952982631. The cubic root of 81400008 is about 433.3859381239.

The spelling of 81400008 in words is "eighty-one million, four hundred thousand, eight".