87521901 has 4 divisors (see below), whose sum is σ = 116695872. Its totient is φ = 58347932.

The previous prime is 87521879. The next prime is 87521989. The reversal of 87521901 is 10912578.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87521901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87521701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14586981 + ... + 14586986.

It is an arithmetic number, because the mean of its divisors is an integer number (29173968).

Almost surely, 2^87521901 is an apocalyptic number.

It is an amenable number.

87521901 is a deficient number, since it is larger than the sum of its proper divisors (29173971).

87521901 is a wasteful number, since it uses less digits than its factorization.

87521901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29173970.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 87521901 is about 9355.3140513828. The cubic root of 87521901 is about 443.9890377539.

The spelling of 87521901 in words is "eighty-seven million, five hundred twenty-one thousand, nine hundred one".