51561413 has 4 divisors (see below), whose sum is σ = 51757728. Its totient is φ = 51365100.

The previous prime is 51561379. The next prime is 51561427. The reversal of 51561413 is 31416515.

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 51561413 - 2⁸ = 51561157 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 (51561443) 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, 97763 + ... + 98288.

It is an arithmetic number, because the mean of its divisors is an integer number (12939432).

Almost surely, 2^51561413 is an apocalyptic number.

It is an amenable number.

51561413 is a deficient number, since it is larger than the sum of its proper divisors (196315).

51561413 is a wasteful number, since it uses less digits than its factorization.

51561413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196314.

The product of its digits is 1800, while the sum is 26.

The square root of 51561413 is about 7180.6276188088. The cubic root of 51561413 is about 372.1987727346.

Adding to 51561413 its reverse (31416515), we get a palindrome (82977928).

The spelling of 51561413 in words is "fifty-one million, five hundred sixty-one thousand, four hundred thirteen".