626538421 has 2 divisors, whose sum is σ = 626538422. Its totient is φ = 626538420.

The previous prime is 626538413. The next prime is 626538457. The reversal of 626538421 is 124835626.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609843025 + 16695396 = 24695^2 + 4086^2 .

It is a cyclic number.

It is not a de Polignac number, because 626538421 - 2³ = 626538413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (626538461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 313269210 + 313269211.

It is an arithmetic number, because the mean of its divisors is an integer number (313269211).

Almost surely, 2^626538421 is an apocalyptic number.

It is an amenable number.

626538421 is a deficient number, since it is larger than the sum of its proper divisors (1).

626538421 is an equidigital number, since it uses as much as digits as its factorization.

626538421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69120, while the sum is 37.

The square root of 626538421 is about 25030.7495093535. The cubic root of 626538421 is about 855.6889086495.

The spelling of 626538421 in words is "six hundred twenty-six million, five hundred thirty-eight thousand, four hundred twenty-one".