61811951 has 4 divisors (see below), whose sum is σ = 61860552. Its totient is φ = 61763352.

The previous prime is 61811929. The next prime is 61811977. The reversal of 61811951 is 15911816.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61811951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61810951) 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, 22340 + ... + 24953.

It is an arithmetic number, because the mean of its divisors is an integer number (15465138).

Almost surely, 2^61811951 is an apocalyptic number.

61811951 is a deficient number, since it is larger than the sum of its proper divisors (48601).

61811951 is a wasteful number, since it uses less digits than its factorization.

61811951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48600.

The product of its digits is 2160, while the sum is 32.

The square root of 61811951 is about 7862.0576823119. The cubic root of 61811951 is about 395.3886065022.

The spelling of 61811951 in words is "sixty-one million, eight hundred eleven thousand, nine hundred fifty-one".