61921117 has 2 divisors, whose sum is σ = 61921118. Its totient is φ = 61921116.

The previous prime is 61921099. The next prime is 61921121. The reversal of 61921117 is 71112916.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60310756 + 1610361 = 7766^2 + 1269^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61921117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61921147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30960558 + 30960559.

It is an arithmetic number, because the mean of its divisors is an integer number (30960559).

Almost surely, 2^61921117 is an apocalyptic number.

It is an amenable number.

61921117 is a deficient number, since it is larger than the sum of its proper divisors (1).

61921117 is an equidigital number, since it uses as much as digits as its factorization.

61921117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 28.

The square root of 61921117 is about 7868.9972042186. The cubic root of 61921117 is about 395.6212346957.

It can be divided in two parts, 619 and 21117, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 61921117 in words is "sixty-one million, nine hundred twenty-one thousand, one hundred seventeen".