61515550939 has 2 divisors, whose sum is σ = 61515550940. Its totient is φ = 61515550938.

The previous prime is 61515550927. The next prime is 61515550949. The reversal of 61515550939 is 93905551516.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61515550939 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61515550892 and 61515550901.

It is not a weakly prime, because it can be changed into another prime (61515550949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30757775469 + 30757775470.

It is an arithmetic number, because the mean of its divisors is an integer number (30757775470).

Almost surely, 2^61515550939 is an apocalyptic number.

61515550939 is a deficient number, since it is larger than the sum of its proper divisors (1).

61515550939 is an equidigital number, since it uses as much as digits as its factorization.

61515550939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 911250, while the sum is 49.

The spelling of 61515550939 in words is "sixty-one billion, five hundred fifteen million, five hundred fifty thousand, nine hundred thirty-nine".