61238399021 has 2 divisors, whose sum is σ = 61238399022. Its totient is φ = 61238399020.

The previous prime is 61238399009. The next prime is 61238399069. The reversal of 61238399021 is 12099383216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61083122500 + 155276521 = 247150^2 + 12461^2 .

It is a cyclic number.

It is not a de Polignac number, because 61238399021 - 2³⁰ = 60164657197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61238392021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30619199510 + 30619199511.

It is an arithmetic number, because the mean of its divisors is an integer number (30619199511).

Almost surely, 2^61238399021 is an apocalyptic number.

It is an amenable number.

61238399021 is a deficient number, since it is larger than the sum of its proper divisors (1).

61238399021 is an equidigital number, since it uses as much as digits as its factorization.

61238399021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 44.

The spelling of 61238399021 in words is "sixty-one billion, two hundred thirty-eight million, three hundred ninety-nine thousand, twenty-one".