51535391 has 4 divisors (see below), whose sum is σ = 54247800. Its totient is φ = 48822984.

The previous prime is 51535369. The next prime is 51535409. The reversal of 51535391 is 19353515.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19353515 = 5 ⋅3870703.

It is a cyclic number.

It is not a de Polignac number, because 51535391 - 2¹⁰ = 51534367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51535321) 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, 1356176 + ... + 1356213.

It is an arithmetic number, because the mean of its divisors is an integer number (13561950).

Almost surely, 2^51535391 is an apocalyptic number.

51535391 is a deficient number, since it is larger than the sum of its proper divisors (2712409).

51535391 is a wasteful number, since it uses less digits than its factorization.

51535391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2712408.

The product of its digits is 10125, while the sum is 32.

The square root of 51535391 is about 7178.8154315319. The cubic root of 51535391 is about 372.1361484730.

The spelling of 51535391 in words is "fifty-one million, five hundred thirty-five thousand, three hundred ninety-one".