51521807 has 2 divisors, whose sum is σ = 51521808. Its totient is φ = 51521806.

The previous prime is 51521803. The next prime is 51521843. The reversal of 51521807 is 70812515.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51521807 - 2² = 51521803 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51521807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51521801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25760903 + 25760904.

It is an arithmetic number, because the mean of its divisors is an integer number (25760904).

Almost surely, 2^51521807 is an apocalyptic number.

51521807 is a deficient number, since it is larger than the sum of its proper divisors (1).

51521807 is an equidigital number, since it uses as much as digits as its factorization.

51521807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2800, while the sum is 29.

The square root of 51521807 is about 7177.8692520831. The cubic root of 51521807 is about 372.1034489917.

It can be divided in two parts, 515 and 21807, that added together give a palindrome (22322).

The spelling of 51521807 in words is "fifty-one million, five hundred twenty-one thousand, eight hundred seven".