51827621 has 4 divisors (see below), whose sum is σ = 51943500. Its totient is φ = 51711744.

The previous prime is 51827617. The next prime is 51827627. The reversal of 51827621 is 12672815.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12672815 = 5 ⋅2534563.

It can be written as a sum of positive squares in 2 ways, for example, as 20802721 + 31024900 = 4561^2 + 5570^2 .

It is a cyclic number.

It is not a de Polignac number, because 51827621 - 2² = 51827617 is a prime.

It is a super-2 number, since 2×51827621² = 5372204597039282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51827627) 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, 57266 + ... + 58163.

It is an arithmetic number, because the mean of its divisors is an integer number (12985875).

Almost surely, 2^51827621 is an apocalyptic number.

It is an amenable number.

51827621 is a deficient number, since it is larger than the sum of its proper divisors (115879).

51827621 is a wasteful number, since it uses less digits than its factorization.

51827621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115878.

The product of its digits is 6720, while the sum is 32.

The square root of 51827621 is about 7199.1402958964. The cubic root of 51827621 is about 372.8382190067.

The spelling of 51827621 in words is "fifty-one million, eight hundred twenty-seven thousand, six hundred twenty-one".