74643781 has 4 divisors (see below), whose sum is σ = 74664064. Its totient is φ = 74623500.

The previous prime is 74643773. The next prime is 74643827. The reversal of 74643781 is 18734647.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18734647 = 73 ⋅256639.

It is a cyclic number.

It is not a de Polignac number, because 74643781 - 2³ = 74643773 is a prime.

It is a super-2 number, since 2×74643781² = 11143388083951922, 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 (74643281) 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, 2895 + ... + 12556.

It is an arithmetic number, because the mean of its divisors is an integer number (18666016).

Almost surely, 2^74643781 is an apocalyptic number.

It is an amenable number.

74643781 is a deficient number, since it is larger than the sum of its proper divisors (20283).

74643781 is a wasteful number, since it uses less digits than its factorization.

74643781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20282.

The product of its digits is 112896, while the sum is 40.

The square root of 74643781 is about 8639.6632457521. The cubic root of 74643781 is about 421.0476133939.

The spelling of 74643781 in words is "seventy-four million, six hundred forty-three thousand, seven hundred eighty-one".