61917619 has 2 divisors, whose sum is σ = 61917620. Its totient is φ = 61917618.

The previous prime is 61917617. The next prime is 61917629. The reversal of 61917619 is 91671916.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61917619 - 2¹ = 61917617 is a prime.

It is a super-2 number, since 2×61917619² = 7667583085258322, which contains 22 as substring.

Together with 61917617, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (61917617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30958809 + 30958810.

It is an arithmetic number, because the mean of its divisors is an integer number (30958810).

Almost surely, 2^61917619 is an apocalyptic number.

61917619 is a deficient number, since it is larger than the sum of its proper divisors (1).

61917619 is an equidigital number, since it uses as much as digits as its factorization.

61917619 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 40.

The square root of 61917619 is about 7868.7749364180. The cubic root of 61917619 is about 395.6137848455.

The spelling of 61917619 in words is "sixty-one million, nine hundred seventeen thousand, six hundred nineteen".