51165021 has 4 divisors (see below), whose sum is σ = 68220032. Its totient is φ = 34110012.

The previous prime is 51165013. The next prime is 51165029. The reversal of 51165021 is 12056115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (51165013) and next prime (51165029).

It is not a de Polignac number, because 51165021 - 2³ = 51165013 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 (51165029) 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, 8527501 + ... + 8527506.

It is an arithmetic number, because the mean of its divisors is an integer number (17055008).

Almost surely, 2^51165021 is an apocalyptic number.

It is an amenable number.

51165021 is a deficient number, since it is larger than the sum of its proper divisors (17055011).

51165021 is a wasteful number, since it uses less digits than its factorization.

51165021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17055010.

The product of its (nonzero) digits is 300, while the sum is 21.

The square root of 51165021 is about 7152.9728784611. The cubic root of 51165021 is about 371.2425258956.

The spelling of 51165021 in words is "fifty-one million, one hundred sixty-five thousand, twenty-one".