87221555 has 8 divisors (see below), whose sum is σ = 107218944. Its totient is φ = 68075200.

The previous prime is 87221551. The next prime is 87221567. The reversal of 87221555 is 55512278.

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

It is not a de Polignac number, because 87221555 - 2² = 87221551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87221551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212531 + ... + 212940.

It is an arithmetic number, because the mean of its divisors is an integer number (13402368).

Almost surely, 2^87221555 is an apocalyptic number.

87221555 is a deficient number, since it is larger than the sum of its proper divisors (19997389).

87221555 is a wasteful number, since it uses less digits than its factorization.

87221555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425517.

The product of its digits is 28000, while the sum is 35.

The square root of 87221555 is about 9339.2480960728. The cubic root of 87221555 is about 443.4805815486.

The spelling of 87221555 in words is "eighty-seven million, two hundred twenty-one thousand, five hundred fifty-five".