74905991921 has 2 divisors, whose sum is σ = 74905991922. Its totient is φ = 74905991920.

The previous prime is 74905991903. The next prime is 74905991929. The reversal of 74905991921 is 12919950947.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47050381921 + 27855610000 = 216911^2 + 166900^2 .

It is a cyclic number.

It is not a de Polignac number, because 74905991921 - 2¹⁸ = 74905729777 is a prime.

It is a super-2 number, since 2×74905991921² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (74905991929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37452995960 + 37452995961.

It is an arithmetic number, because the mean of its divisors is an integer number (37452995961).

Almost surely, 2^74905991921 is an apocalyptic number.

It is an amenable number.

74905991921 is a deficient number, since it is larger than the sum of its proper divisors (1).

74905991921 is an equidigital number, since it uses as much as digits as its factorization.

74905991921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1837080, while the sum is 56.

The spelling of 74905991921 in words is "seventy-four billion, nine hundred five million, nine hundred ninety-one thousand, nine hundred twenty-one".