87138493 has 8 divisors (see below), whose sum is σ = 94165848. Its totient is φ = 80157504.

The previous prime is 87138479. The next prime is 87138497. The reversal of 87138493 is 39483178.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 35557369 + 51581124 = 5963^2 + 7182^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87138493 is a prime.

It is a super-2 number, since 2×87138493² = 15186233924622098, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87138497) 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 7 ways as a sum of consecutive naturals, for example, 7630 + ... + 15247.

It is an arithmetic number, because the mean of its divisors is an integer number (11770731).

Almost surely, 2^87138493 is an apocalyptic number.

It is an amenable number.

87138493 is a deficient number, since it is larger than the sum of its proper divisors (7027355).

87138493 is a wasteful number, since it uses less digits than its factorization.

87138493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23183.

The product of its digits is 145152, while the sum is 43.

The square root of 87138493 is about 9334.8001049835. The cubic root of 87138493 is about 443.3397597702.

The spelling of 87138493 in words is "eighty-seven million, one hundred thirty-eight thousand, four hundred ninety-three".