76431521 has 4 divisors (see below), whose sum is σ = 77033472. Its totient is φ = 75829572.

The previous prime is 76431499. The next prime is 76431527. The reversal of 76431521 is 12513467.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12513467 = 149 ⋅83983.

It is a cyclic number.

It is not a de Polignac number, because 76431521 - 2¹⁸ = 76169377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76431527) 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, 300785 + ... + 301038.

It is an arithmetic number, because the mean of its divisors is an integer number (19258368).

Almost surely, 2^76431521 is an apocalyptic number.

It is an amenable number.

76431521 is a deficient number, since it is larger than the sum of its proper divisors (601951).

76431521 is a wasteful number, since it uses less digits than its factorization.

76431521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601950.

The product of its digits is 5040, while the sum is 29.

The square root of 76431521 is about 8742.5122819473. The cubic root of 76431521 is about 424.3825330972.

Adding to 76431521 its reverse (12513467), we get a palindrome (88944988).

The spelling of 76431521 in words is "seventy-six million, four hundred thirty-one thousand, five hundred twenty-one".