87921137 has 4 divisors (see below), whose sum is σ = 88012656. Its totient is φ = 87829620.

The previous prime is 87921131. The next prime is 87921143. The reversal of 87921137 is 73112978.

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, and also an emirpimes, since its reverse is a distinct semiprime: 73112978 = 2 ⋅36556489.

It is an interprime number because it is at equal distance from previous prime (87921131) and next prime (87921143).

It is a cyclic number.

It is not a de Polignac number, because 87921137 - 2⁴ = 87921121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87921137.

It is not an unprimeable number, because it can be changed into a prime (87921131) 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, 44303 + ... + 46244.

It is an arithmetic number, because the mean of its divisors is an integer number (22003164).

Almost surely, 2^87921137 is an apocalyptic number.

It is an amenable number.

87921137 is a deficient number, since it is larger than the sum of its proper divisors (91519).

87921137 is an equidigital number, since it uses as much as digits as its factorization.

87921137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91518.

The product of its digits is 21168, while the sum is 38.

The square root of 87921137 is about 9376.6271654577. The cubic root of 87921137 is about 444.6631073858.

The spelling of 87921137 in words is "eighty-seven million, nine hundred twenty-one thousand, one hundred thirty-seven".