61917851 has 2 divisors, whose sum is σ = 61917852. Its totient is φ = 61917850.

The previous prime is 61917841. The next prime is 61917857. The reversal of 61917851 is 15871916.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61917851 - 2⁶ = 61917787 is a prime.

It is not a weakly prime, because it can be changed into another prime (61917857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30958925 + 30958926.

It is an arithmetic number, because the mean of its divisors is an integer number (30958926).

Almost surely, 2^61917851 is an apocalyptic number.

61917851 is a deficient number, since it is larger than the sum of its proper divisors (1).

61917851 is an equidigital number, since it uses as much as digits as its factorization.

61917851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 38.

The square root of 61917851 is about 7868.7896782161. The cubic root of 61917851 is about 395.6142789551.

The spelling of 61917851 in words is "sixty-one million, nine hundred seventeen thousand, eight hundred fifty-one".