621642031 has 2 divisors, whose sum is σ = 621642032. Its totient is φ = 621642030.

The previous prime is 621642023. The next prime is 621642037. The reversal of 621642031 is 130246126.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 621642031 - 2³ = 621642023 is a prime.

It is a super-2 number, since 2×621642031² = 772877629411609922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 621641987 and 621642005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621642037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310821015 + 310821016.

It is an arithmetic number, because the mean of its divisors is an integer number (310821016).

Almost surely, 2^621642031 is an apocalyptic number.

621642031 is a deficient number, since it is larger than the sum of its proper divisors (1).

621642031 is an equidigital number, since it uses as much as digits as its factorization.

621642031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 621642031 is about 24932.7501692052. The cubic root of 621642031 is about 853.4540105245.

Adding to 621642031 its reverse (130246126), we get a palindrome (751888157).

The spelling of 621642031 in words is "six hundred twenty-one million, six hundred forty-two thousand, thirty-one".