656139251 has 2 divisors, whose sum is σ = 656139252. Its totient is φ = 656139250.

The previous prime is 656139229. The next prime is 656139271. The reversal of 656139251 is 152931656.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 656139251 - 2²² = 651944947 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (656139271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328069625 + 328069626.

It is an arithmetic number, because the mean of its divisors is an integer number (328069626).

Almost surely, 2^656139251 is an apocalyptic number.

656139251 is a deficient number, since it is larger than the sum of its proper divisors (1).

656139251 is an equidigital number, since it uses as much as digits as its factorization.

656139251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48600, while the sum is 38.

The square root of 656139251 is about 25615.2152245496. The cubic root of 656139251 is about 868.9577738397.

It can be divided in two parts, 65 and 6139251, that added together give a palindrome (6139316).

The spelling of 656139251 in words is "six hundred fifty-six million, one hundred thirty-nine thousand, two hundred fifty-one".