51055021 has 4 divisors (see below), whose sum is σ = 51221632. Its totient is φ = 50888412.

The previous prime is 51055013. The next prime is 51055027. The reversal of 51055021 is 12055015.

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 a cyclic number.

It is not a de Polignac number, because 51055021 - 2³ = 51055013 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51055021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51055027) 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, 82845 + ... + 83458.

It is an arithmetic number, because the mean of its divisors is an integer number (12805408).

Almost surely, 2^51055021 is an apocalyptic number.

It is an amenable number.

51055021 is a deficient number, since it is larger than the sum of its proper divisors (166611).

51055021 is a wasteful number, since it uses less digits than its factorization.

51055021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166610.

The product of its (nonzero) digits is 250, while the sum is 19.

The square root of 51055021 is about 7145.2796306373. The cubic root of 51055021 is about 370.9762894639.

The spelling of 51055021 in words is "fifty-one million, fifty-five thousand, twenty-one".