87402821 has 4 divisors (see below), whose sum is σ = 95348544. Its totient is φ = 79457100.

The previous prime is 87402817. The next prime is 87402841. The reversal of 87402821 is 12820478.

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 not a de Polignac number, because 87402821 - 2² = 87402817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87402841) 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 3 ways as a sum of consecutive naturals, for example, 3972845 + ... + 3972866.

It is an arithmetic number, because the mean of its divisors is an integer number (23837136).

Almost surely, 2^87402821 is an apocalyptic number.

It is an amenable number.

87402821 is a deficient number, since it is larger than the sum of its proper divisors (7945723).

87402821 is a wasteful number, since it uses less digits than its factorization.

87402821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7945722.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 87402821 is about 9348.9475878304. The cubic root of 87402821 is about 443.7875864215.

The spelling of 87402821 in words is "eighty-seven million, four hundred two thousand, eight hundred twenty-one".