74724021 has 24 divisors (see below), whose sum is σ = 110096064. Its totient is φ = 48827520.

The previous prime is 74724007. The next prime is 74724059. The reversal of 74724021 is 12042747.

It is a happy number.

It is not a de Polignac number, because 74724021 - 2⁵ = 74723989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (74724421) 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 23 ways as a sum of consecutive naturals, for example, 215170 + ... + 215516.

It is an arithmetic number, because the mean of its divisors is an integer number (4587336).

Almost surely, 2^74724021 is an apocalyptic number.

74724021 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

It is an amenable number.

74724021 is a deficient number, since it is larger than the sum of its proper divisors (35372043).

74724021 is a wasteful number, since it uses less digits than its factorization.

74724021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 74724021 is about 8644.3056979725. The cubic root of 74724021 is about 421.1984308781.

Adding to 74724021 its reverse (12042747), we get a palindrome (86766768).

The spelling of 74724021 in words is "seventy-four million, seven hundred twenty-four thousand, twenty-one".