21487369 has 8 divisors (see below), whose sum is σ = 22120128. Its totient is φ = 20863920.

The previous prime is 21487351. The next prime is 21487373. The reversal of 21487369 is 96378412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21487369 is a prime.

It is a super-2 number, since 2×21487369² = 923414053084322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21487469) 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, 2499 + ... + 7015.

It is an arithmetic number, because the mean of its divisors is an integer number (2765016).

Almost surely, 2^21487369 is an apocalyptic number.

It is an amenable number.

21487369 is a deficient number, since it is larger than the sum of its proper divisors (632759).

21487369 is an equidigital number, since it uses as much as digits as its factorization.

21487369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4655.

The product of its digits is 72576, while the sum is 40.

The square root of 21487369 is about 4635.4470118857. The cubic root of 21487369 is about 278.0104243628.

The spelling of 21487369 in words is "twenty-one million, four hundred eighty-seven thousand, three hundred sixty-nine".