865406421 has 12 divisors (see below), whose sum is σ = 1363670880. Its totient is φ = 524488680.

The previous prime is 865406413. The next prime is 865406483. The reversal of 865406421 is 124604568.

865406421 is a `hidden beast` number, since 8 + 6 + 5 + 4 + 0 + 642 + 1 = 666.

It is not a de Polignac number, because 865406421 - 2³ = 865406413 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865406411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4370641 + ... + 4370838.

It is an arithmetic number, because the mean of its divisors is an integer number (113639240).

Almost surely, 2^865406421 is an apocalyptic number.

It is an amenable number.

865406421 is a deficient number, since it is larger than the sum of its proper divisors (498264459).

865406421 is a wasteful number, since it uses less digits than its factorization.

865406421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8741496 (or 8741493 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 865406421 is about 29417.7908925874. The cubic root of 865406421 is about 952.9571459688.

The spelling of 865406421 in words is "eight hundred sixty-five million, four hundred six thousand, four hundred twenty-one".