87438921 has 4 divisors (see below), whose sum is σ = 116585232. Its totient is φ = 58292612.

The previous prime is 87438919. The next prime is 87438961. The reversal of 87438921 is 12983478.

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.

It is a cyclic number.

It is not a de Polignac number, because 87438921 - 2¹ = 87438919 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (87438961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14573151 + ... + 14573156.

It is an arithmetic number, because the mean of its divisors is an integer number (29146308).

Almost surely, 2^87438921 is an apocalyptic number.

It is an amenable number.

87438921 is a deficient number, since it is larger than the sum of its proper divisors (29146311).

87438921 is a wasteful number, since it uses less digits than its factorization.

87438921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29146310.

The product of its digits is 96768, while the sum is 42.

The square root of 87438921 is about 9350.8780871103. The cubic root of 87438921 is about 443.8486772288.

The spelling of 87438921 in words is "eighty-seven million, four hundred thirty-eight thousand, nine hundred twenty-one".