39855472621 has 2 divisors, whose sum is σ = 39855472622. Its totient is φ = 39855472620.

The previous prime is 39855472567. The next prime is 39855472633. The reversal of 39855472621 is 12627455893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27121478596 + 12733994025 = 164686^2 + 112845^2 .

It is a cyclic number.

It is not a de Polignac number, because 39855472621 - 2²¹ = 39853375469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39855472661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19927736310 + 19927736311.

It is an arithmetic number, because the mean of its divisors is an integer number (19927736311).

Almost surely, 2^39855472621 is an apocalyptic number.

It is an amenable number.

39855472621 is a deficient number, since it is larger than the sum of its proper divisors (1).

39855472621 is an equidigital number, since it uses as much as digits as its factorization.

39855472621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3628800, while the sum is 52.

The spelling of 39855472621 in words is "thirty-nine billion, eight hundred fifty-five million, four hundred seventy-two thousand, six hundred twenty-one".