75139521 has 8 divisors (see below), whose sum is σ = 100248864. Its totient is φ = 50061600.

The previous prime is 75139517. The next prime is 75139523. The reversal of 75139521 is 12593157.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 75139521 - 2² = 75139517 is a prime.

It is a super-2 number, since 2×75139521² = 11291895232218882, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (75139523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1551 + ... + 12356.

It is an arithmetic number, because the mean of its divisors is an integer number (12531108).

Almost surely, 2^75139521 is an apocalyptic number.

It is an amenable number.

75139521 is a deficient number, since it is larger than the sum of its proper divisors (25109343).

75139521 is a wasteful number, since it uses less digits than its factorization.

75139521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15711.

The product of its digits is 9450, while the sum is 33.

The square root of 75139521 is about 8668.3055437611. The cubic root of 75139521 is about 421.9776741481.

The spelling of 75139521 in words is "seventy-five million, one hundred thirty-nine thousand, five hundred twenty-one".