75321921 has 4 divisors (see below), whose sum is σ = 100429232. Its totient is φ = 50214612.

The previous prime is 75321913. The next prime is 75321931. The reversal of 75321921 is 12912357.

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.

It is not a de Polignac number, because 75321921 - 2³ = 75321913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75321931) 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, 12553651 + ... + 12553656.

It is an arithmetic number, because the mean of its divisors is an integer number (25107308).

Almost surely, 2^75321921 is an apocalyptic number.

It is an amenable number.

75321921 is a deficient number, since it is larger than the sum of its proper divisors (25107311).

75321921 is a wasteful number, since it uses less digits than its factorization.

75321921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25107310.

The product of its digits is 3780, while the sum is 30.

The square root of 75321921 is about 8678.8202539285. The cubic root of 75321921 is about 422.3188462791.

It can be divided in two parts, 7532 and 1921, that added together give a triangular number (9453 = T₁₃₇).

The spelling of 75321921 in words is "seventy-five million, three hundred twenty-one thousand, nine hundred twenty-one".