87521831 has 8 divisors (see below), whose sum is σ = 96699744. Its totient is φ = 78791680.

The previous prime is 87521821. The next prime is 87521843. The reversal of 87521831 is 13812578.

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

It is a cyclic number.

It is not a de Polignac number, because 87521831 - 2¹⁴ = 87505447 is a prime.

It is a super-2 number, since 2×87521831² = 15320141803185122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 87521791 and 87521800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87521821) 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, 111530 + ... + 112311.

It is an arithmetic number, because the mean of its divisors is an integer number (12087468).

Almost surely, 2^87521831 is an apocalyptic number.

87521831 is a deficient number, since it is larger than the sum of its proper divisors (9177913).

87521831 is a wasteful number, since it uses less digits than its factorization.

87521831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223881.

The product of its digits is 13440, while the sum is 35.

The square root of 87521831 is about 9355.3103101928. The cubic root of 87521831 is about 443.9889193864.

The spelling of 87521831 in words is "eighty-seven million, five hundred twenty-one thousand, eight hundred thirty-one".