21487364 has 6 divisors (see below), whose sum is σ = 37602894. Its totient is φ = 10743680.

The previous prime is 21487351. The next prime is 21487373. The reversal of 21487364 is 46378412.

It can be written as a sum of positive squares in only one way, i.e., 12902464 + 8584900 = 3592^2 + 2930^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2685917 + ... + 2685924.

It is an arithmetic number, because the mean of its divisors is an integer number (6267149).

Almost surely, 2^21487364 is an apocalyptic number.

It is an amenable number.

21487364 is a deficient number, since it is larger than the sum of its proper divisors (16115530).

21487364 is a wasteful number, since it uses less digits than its factorization.

21487364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5371845 (or 5371843 counting only the distinct ones).

The product of its digits is 32256, while the sum is 35.

The square root of 21487364 is about 4635.4464725633. The cubic root of 21487364 is about 278.0104027990.

It can be divided in two parts, 214 and 87364, that added together give a palindrome (87578).

The spelling of 21487364 in words is "twenty-one million, four hundred eighty-seven thousand, three hundred sixty-four".