61615987 has 2 divisors, whose sum is σ = 61615988. Its totient is φ = 61615986.

The previous prime is 61615969. The next prime is 61615999. The reversal of 61615987 is 78951616.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61615987 is a prime.

It is not a weakly prime, because it can be changed into another prime (61615927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30807993 + 30807994.

It is an arithmetic number, because the mean of its divisors is an integer number (30807994).

Almost surely, 2^61615987 is an apocalyptic number.

61615987 is a deficient number, since it is larger than the sum of its proper divisors (1).

61615987 is an equidigital number, since it uses as much as digits as its factorization.

61615987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 61615987 is about 7849.5851482738. The cubic root of 61615987 is about 394.9703273122.

The spelling of 61615987 in words is "sixty-one million, six hundred fifteen thousand, nine hundred eighty-seven".