61563979 has 2 divisors, whose sum is σ = 61563980. Its totient is φ = 61563978.

The previous prime is 61563961. The next prime is 61564037. The reversal of 61563979 is 97936516.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61563979 - 2¹¹ = 61561931 is a prime.

It is not a weakly prime, because it can be changed into another prime (61563379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30781989 + 30781990.

It is an arithmetic number, because the mean of its divisors is an integer number (30781990).

Almost surely, 2^61563979 is an apocalyptic number.

61563979 is a deficient number, since it is larger than the sum of its proper divisors (1).

61563979 is an equidigital number, since it uses as much as digits as its factorization.

61563979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 306180, while the sum is 46.

The square root of 61563979 is about 7846.2716623884. The cubic root of 61563979 is about 394.8591689371.

The spelling of 61563979 in words is "sixty-one million, five hundred sixty-three thousand, nine hundred seventy-nine".