61499891 has 2 divisors, whose sum is σ = 61499892. Its totient is φ = 61499890.

The previous prime is 61499887. The next prime is 61499983. The reversal of 61499891 is 19899416.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61499891 - 2² = 61499887 is a prime.

It is not a weakly prime, because it can be changed into another prime (61499881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30749945 + 30749946.

It is an arithmetic number, because the mean of its divisors is an integer number (30749946).

Almost surely, 2^61499891 is an apocalyptic number.

61499891 is a deficient number, since it is larger than the sum of its proper divisors (1).

61499891 is an equidigital number, since it uses as much as digits as its factorization.

61499891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 47.

The square root of 61499891 is about 7842.1866210898. The cubic root of 61499891 is about 394.7221054519.

The spelling of 61499891 in words is "sixty-one million, four hundred ninety-nine thousand, eight hundred ninety-one".