51402021 has 8 divisors (see below), whose sum is σ = 74766624. Its totient is φ = 31152720.

The previous prime is 51402019. The next prime is 51402037. The reversal of 51402021 is 12020415.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51402021 - 2¹ = 51402019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51402041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 778786 + ... + 778851.

It is an arithmetic number, because the mean of its divisors is an integer number (9345828).

Almost surely, 2^51402021 is an apocalyptic number.

It is an amenable number.

51402021 is a deficient number, since it is larger than the sum of its proper divisors (23364603).

51402021 is a wasteful number, since it uses less digits than its factorization.

51402021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1557651.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 51402021 is about 7169.5202768386. The cubic root of 51402021 is about 371.8148503426.

Adding to 51402021 its reverse (12020415), we get a palindrome (63422436).

The spelling of 51402021 in words is "fifty-one million, four hundred two thousand, twenty-one".