61660390399 has 2 divisors, whose sum is σ = 61660390400. Its totient is φ = 61660390398.

The previous prime is 61660390387. The next prime is 61660390403. The reversal of 61660390399 is 99309306616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61660390399 - 2¹³ = 61660382207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61660390499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30830195199 + 30830195200.

It is an arithmetic number, because the mean of its divisors is an integer number (30830195200).

Almost surely, 2^61660390399 is an apocalyptic number.

61660390399 is a deficient number, since it is larger than the sum of its proper divisors (1).

61660390399 is an equidigital number, since it uses as much as digits as its factorization.

61660390399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1417176, while the sum is 52.

The spelling of 61660390399 in words is "sixty-one billion, six hundred sixty million, three hundred ninety thousand, three hundred ninety-nine".