30639755621 has 2 divisors, whose sum is σ = 30639755622. Its totient is φ = 30639755620.

The previous prime is 30639755539. The next prime is 30639755717. The reversal of 30639755621 is 12655793603.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30159532225 + 480223396 = 173665^2 + 21914^2 .

It is a cyclic number.

It is not a de Polignac number, because 30639755621 - 2²⁶ = 30572646757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30639755821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15319877810 + 15319877811.

It is an arithmetic number, because the mean of its divisors is an integer number (15319877811).

Almost surely, 2^30639755621 is an apocalyptic number.

It is an amenable number.

30639755621 is a deficient number, since it is larger than the sum of its proper divisors (1).

30639755621 is an equidigital number, since it uses as much as digits as its factorization.

30639755621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1020600, while the sum is 47.

The spelling of 30639755621 in words is "thirty billion, six hundred thirty-nine million, seven hundred fifty-five thousand, six hundred twenty-one".