87381913 has 4 divisors (see below), whose sum is σ = 87864868. Its totient is φ = 86898960.

The previous prime is 87381851. The next prime is 87381919. The reversal of 87381913 is 31918378.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5895184 + 81486729 = 2428^2 + 9027^2 .

It is a cyclic number.

It is not a de Polignac number, because 87381913 - 2⁹ = 87381401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87381919) 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, 241206 + ... + 241567.

It is an arithmetic number, because the mean of its divisors is an integer number (21966217).

Almost surely, 2^87381913 is an apocalyptic number.

It is an amenable number.

87381913 is a deficient number, since it is larger than the sum of its proper divisors (482955).

87381913 is a wasteful number, since it uses less digits than its factorization.

87381913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482954.

The product of its digits is 36288, while the sum is 40.

The square root of 87381913 is about 9347.8293202219. The cubic root of 87381913 is about 443.7521968284.

The spelling of 87381913 in words is "eighty-seven million, three hundred eighty-one thousand, nine hundred thirteen".