87644421 has 12 divisors (see below), whose sum is σ = 132102048. Its totient is φ = 55889064.

The previous prime is 87644419. The next prime is 87644437. The reversal of 87644421 is 12444678.

87644421 is a `hidden beast` number, since 8 + 7 + 644 + 4 + 2 + 1 = 666.

It is not a de Polignac number, because 87644421 - 2¹ = 87644419 is a prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87644411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 211495 + ... + 211908.

It is an arithmetic number, because the mean of its divisors is an integer number (11008504).

Almost surely, 2^87644421 is an apocalyptic number.

It is an amenable number.

87644421 is a deficient number, since it is larger than the sum of its proper divisors (44457627).

87644421 is a wasteful number, since it uses less digits than its factorization.

87644421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423432 (or 423429 counting only the distinct ones).

The product of its digits is 43008, while the sum is 36.

The square root of 87644421 is about 9361.8599113638. The cubic root of 87644421 is about 444.1961180111.

The spelling of 87644421 in words is "eighty-seven million, six hundred forty-four thousand, four hundred twenty-one".