87390421 has 12 divisors (see below), whose sum is σ = 94163040. Its totient is φ = 81072320.

The previous prime is 87390389. The next prime is 87390449. The reversal of 87390421 is 12409378.

It is not a de Polignac number, because 87390421 - 2⁵ = 87390389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87390461) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18390 + ... + 22648.

It is an arithmetic number, because the mean of its divisors is an integer number (7846920).

Almost surely, 2^87390421 is an apocalyptic number.

It is an amenable number.

87390421 is a deficient number, since it is larger than the sum of its proper divisors (6772619).

87390421 is a wasteful number, since it uses less digits than its factorization.

87390421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4364 (or 4347 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 87390421 is about 9348.2843880575. The cubic root of 87390421 is about 443.7665984402.

Adding to 87390421 its reverse (12409378), we get a palindrome (99799799).

The spelling of 87390421 in words is "eighty-seven million, three hundred ninety thousand, four hundred twenty-one".