74268757721 has 2 divisors, whose sum is σ = 74268757722. Its totient is φ = 74268757720.

The previous prime is 74268757691. The next prime is 74268757733. The reversal of 74268757721 is 12775786247.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40499550025 + 33769207696 = 201245^2 + 183764^2 .

It is a cyclic number.

It is not a de Polignac number, because 74268757721 - 2⁶ = 74268757657 is a prime.

It is a super-2 number, since 2×74268757721² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (74268757741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37134378860 + 37134378861.

It is an arithmetic number, because the mean of its divisors is an integer number (37134378861).

Almost surely, 2^74268757721 is an apocalyptic number.

It is an amenable number.

74268757721 is a deficient number, since it is larger than the sum of its proper divisors (1).

74268757721 is an equidigital number, since it uses as much as digits as its factorization.

74268757721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9219840, while the sum is 56.

The spelling of 74268757721 in words is "seventy-four billion, two hundred sixty-eight million, seven hundred fifty-seven thousand, seven hundred twenty-one".