87372421 has 4 divisors (see below), whose sum is σ = 87392844. Its totient is φ = 87352000.

The previous prime is 87372413. The next prime is 87372427. The reversal of 87372421 is 12427378.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12427378 = 2 ⋅6213689.

It can be written as a sum of positive squares in 2 ways, for example, as 21031396 + 66341025 = 4586^2 + 8145^2 .

It is a cyclic number.

It is not a de Polignac number, because 87372421 - 2³ = 87372413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87372427) 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, 1060 + ... + 13261.

It is an arithmetic number, because the mean of its divisors is an integer number (21848211).

Almost surely, 2^87372421 is an apocalyptic number.

It is an amenable number.

87372421 is a deficient number, since it is larger than the sum of its proper divisors (20423).

87372421 is a wasteful number, since it uses less digits than its factorization.

87372421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20422.

The product of its digits is 18816, while the sum is 34.

The square root of 87372421 is about 9347.3215949811. The cubic root of 87372421 is about 443.7361284826.

Adding to 87372421 its reverse (12427378), we get a palindrome (99799799).

The spelling of 87372421 in words is "eighty-seven million, three hundred seventy-two thousand, four hundred twenty-one".