87021658 has 4 divisors (see below), whose sum is σ = 130532490. Its totient is φ = 43510828.

The previous prime is 87021629. The next prime is 87021659. The reversal of 87021658 is 85612078.

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

It can be written as a sum of positive squares in only one way, i.e., 74183769 + 12837889 = 8613^2 + 3583^2 .

It is a super-2 number, since 2×87021658² = 15145537922137928, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (87021659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21755413 + ... + 21755416.

Almost surely, 2^87021658 is an apocalyptic number.

87021658 is a deficient number, since it is larger than the sum of its proper divisors (43510832).

87021658 is a wasteful number, since it uses less digits than its factorization.

87021658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43510831.

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 87021658 is about 9328.5399715068. The cubic root of 87021658 is about 443.1415283253.

The spelling of 87021658 in words is "eighty-seven million, twenty-one thousand, six hundred fifty-eight".