61813971 has 12 divisors (see below), whose sum is σ = 90291240. Its totient is φ = 40745760.

The previous prime is 61813963. The next prime is 61813981. The reversal of 61813971 is 17931816.

61813971 is a `hidden beast` number, since 618 + 1 + 39 + 7 + 1 = 666.

It is not a de Polignac number, because 61813971 - 2³ = 61813963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61813901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37785 + ... + 39386.

It is an arithmetic number, because the mean of its divisors is an integer number (7524270).

Almost surely, 2^61813971 is an apocalyptic number.

61813971 is a deficient number, since it is larger than the sum of its proper divisors (28477269).

61813971 is a wasteful number, since it uses less digits than its factorization.

61813971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77266 (or 77263 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 61813971 is about 7862.1861463590. The cubic root of 61813971 is about 395.3929135241.

The spelling of 61813971 in words is "sixty-one million, eight hundred thirteen thousand, nine hundred seventy-one".