74905721 has 4 divisors (see below), whose sum is σ = 81715344. Its totient is φ = 68096100.

The previous prime is 74905717. The next prime is 74905769. The reversal of 74905721 is 12750947.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 74905721 - 2² = 74905717 is a prime.

It is a super-2 number, since 2×74905721² = 11221734077059682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (74905711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3404795 + ... + 3404816.

It is an arithmetic number, because the mean of its divisors is an integer number (20428836).

Almost surely, 2^74905721 is an apocalyptic number.

It is an amenable number.

74905721 is a deficient number, since it is larger than the sum of its proper divisors (6809623).

74905721 is a wasteful number, since it uses less digits than its factorization.

74905721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6809622.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 74905721 is about 8654.8091255671. The cubic root of 74905721 is about 421.5395519153.

The spelling of 74905721 in words is "seventy-four million, nine hundred five thousand, seven hundred twenty-one".