81421406 has 16 divisors (see below), whose sum is σ = 133438320. Its totient is φ = 36953280.

The previous prime is 81421393. The next prime is 81421411. The reversal of 81421406 is 60412418.

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, 14210 + ... + 19098.

It is an arithmetic number, because the mean of its divisors is an integer number (8339895).

Almost surely, 2^81421406 is an apocalyptic number.

81421406 is a deficient number, since it is larger than the sum of its proper divisors (52016914).

81421406 is a wasteful number, since it uses less digits than its factorization.

81421406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5659.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 81421406 is about 9023.3810736331. The cubic root of 81421406 is about 433.4239101916.

The spelling of 81421406 in words is "eighty-one million, four hundred twenty-one thousand, four hundred six".