61361891 has 4 divisors (see below), whose sum is σ = 64971432. Its totient is φ = 57752352.

The previous prime is 61361869. The next prime is 61361893. The reversal of 61361891 is 19816316.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61361891 - 2¹⁰ = 61360867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61361893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1804745 + ... + 1804778.

It is an arithmetic number, because the mean of its divisors is an integer number (16242858).

Almost surely, 2^61361891 is an apocalyptic number.

61361891 is a deficient number, since it is larger than the sum of its proper divisors (3609541).

61361891 is a wasteful number, since it uses less digits than its factorization.

61361891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3609540.

The product of its digits is 7776, while the sum is 35.

The square root of 61361891 is about 7833.3831133170. The cubic root of 61361891 is about 394.4266445243.

The spelling of 61361891 in words is "sixty-one million, three hundred sixty-one thousand, eight hundred ninety-one".