74979781 has 4 divisors (see below), whose sum is σ = 75091212. Its totient is φ = 74868352.

The previous prime is 74979743. The next prime is 74979811. The reversal of 74979781 is 18797947.

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

It can be written as a sum of positive squares in 2 ways, for example, as 74114881 + 864900 = 8609^2 + 930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-74979781 is a prime.

It is a super-2 number, since 2×74979781² = 11243935117615922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (74979581) 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, 54700 + ... + 56053.

It is an arithmetic number, because the mean of its divisors is an integer number (18772803).

Almost surely, 2^74979781 is an apocalyptic number.

It is an amenable number.

74979781 is a deficient number, since it is larger than the sum of its proper divisors (111431).

74979781 is a wasteful number, since it uses less digits than its factorization.

74979781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111430.

The product of its digits is 889056, while the sum is 52.

The square root of 74979781 is about 8659.0866146494. The cubic root of 74979781 is about 421.6784328781.

The spelling of 74979781 in words is "seventy-four million, nine hundred seventy-nine thousand, seven hundred eighty-one".