74570821 has 4 divisors (see below), whose sum is σ = 80307052. Its totient is φ = 68834592.

The previous prime is 74570813. The next prime is 74570843. The reversal of 74570821 is 12807547.

It is a happy number.

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 33802596 + 40768225 = 5814^2 + 6385^2 .

It is a cyclic number.

It is not a de Polignac number, because 74570821 - 2³ = 74570813 is a prime.

It is a super-2 number, since 2×74570821² = 11121614689228082, 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 (74570921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2868096 + ... + 2868121.

It is an arithmetic number, because the mean of its divisors is an integer number (20076763).

Almost surely, 2^74570821 is an apocalyptic number.

It is an amenable number.

74570821 is a deficient number, since it is larger than the sum of its proper divisors (5736231).

74570821 is a wasteful number, since it uses less digits than its factorization.

74570821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5736230.

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 74570821 is about 8635.4398266678. The cubic root of 74570821 is about 420.9103854034.

The spelling of 74570821 in words is "seventy-four million, five hundred seventy thousand, eight hundred twenty-one".