74186921 has 2 divisors, whose sum is σ = 74186922. Its totient is φ = 74186920.

The previous prime is 74186899. The next prime is 74186969. The reversal of 74186921 is 12968147.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60762025 + 13424896 = 7795^2 + 3664^2 .

It is an emirp because it is prime and its reverse (12968147) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-74186921 is a prime.

It is not a weakly prime, because it can be changed into another prime (74086921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37093460 + 37093461.

It is an arithmetic number, because the mean of its divisors is an integer number (37093461).

Almost surely, 2^74186921 is an apocalyptic number.

It is an amenable number.

74186921 is a deficient number, since it is larger than the sum of its proper divisors (1).

74186921 is an equidigital number, since it uses as much as digits as its factorization.

74186921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 38.

The square root of 74186921 is about 8613.1829772738. The cubic root of 74186921 is about 420.1868424164.

The spelling of 74186921 in words is "seventy-four million, one hundred eighty-six thousand, nine hundred twenty-one".