75904021 has 4 divisors (see below), whose sum is σ = 76575852. Its totient is φ = 75232192.

The previous prime is 75904019. The next prime is 75904039. The reversal of 75904021 is 12040957.

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 1703025 + 74200996 = 1305^2 + 8614^2 .

It is a cyclic number.

It is not a de Polignac number, because 75904021 - 2¹ = 75904019 is a prime.

It is a super-2 number, since 2×75904021² = 11522840807936882, 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 (75904091) 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, 335746 + ... + 335971.

It is an arithmetic number, because the mean of its divisors is an integer number (19143963).

Almost surely, 2^75904021 is an apocalyptic number.

It is an amenable number.

75904021 is a deficient number, since it is larger than the sum of its proper divisors (671831).

75904021 is a wasteful number, since it uses less digits than its factorization.

75904021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671830.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 75904021 is about 8712.2913748336. The cubic root of 75904021 is about 423.4039718582.

Adding to 75904021 its reverse (12040957), we get a palindrome (87944978).

It can be divided in two parts, 7590 and 4021, that added together give a palindrome (11611).

The spelling of 75904021 in words is "seventy-five million, nine hundred four thousand, twenty-one".