74653977721 has 4 divisors (see below), whose sum is σ = 74686881700. Its totient is φ = 74621073744.

The previous prime is 74653977709. The next prime is 74653977733. The reversal of 74653977721 is 12777935647.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (74653977709) and next prime (74653977733).

It can be written as a sum of positive squares in 2 ways, for example, as 15476604025 + 59177373696 = 124405^2 + 243264^2 .

It is a cyclic number.

It is not a de Polignac number, because 74653977721 - 2²³ = 74645589113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (74653977121) 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, 16448586 + ... + 16453123.

It is an arithmetic number, because the mean of its divisors is an integer number (18671720425).

Almost surely, 2^74653977721 is an apocalyptic number.

It is an amenable number.

74653977721 is a deficient number, since it is larger than the sum of its proper divisors (32903979).

74653977721 is a wasteful number, since it uses less digits than its factorization.

74653977721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32903978.

The product of its digits is 15558480, while the sum is 58.

The spelling of 74653977721 in words is "seventy-four billion, six hundred fifty-three million, nine hundred seventy-seven thousand, seven hundred twenty-one".