51439487 has 4 divisors (see below), whose sum is σ = 56115816. Its totient is φ = 46763160.

The previous prime is 51439471. The next prime is 51439489. The reversal of 51439487 is 78493415.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51439487 - 2⁴ = 51439471 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 (51439489) 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, 2338148 + ... + 2338169.

It is an arithmetic number, because the mean of its divisors is an integer number (14028954).

Almost surely, 2^51439487 is an apocalyptic number.

51439487 is a deficient number, since it is larger than the sum of its proper divisors (4676329).

51439487 is a wasteful number, since it uses less digits than its factorization.

51439487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4676328.

The product of its digits is 120960, while the sum is 41.

The square root of 51439487 is about 7172.1326674846. The cubic root of 51439487 is about 371.9051647682.

The spelling of 51439487 in words is "fifty-one million, four hundred thirty-nine thousand, four hundred eighty-seven".