21379489 has 8 divisors (see below), whose sum is σ = 23621760. Its totient is φ = 19246656.

The previous prime is 21379483. The next prime is 21379493. The reversal of 21379489 is 98497312.

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

It is a cyclic number.

It is not a de Polignac number, because 21379489 - 2³ = 21379481 is a prime.

It is a super-2 number, since 2×21379489² = 914165099802242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21379481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26949 + ... + 27730.

It is an arithmetic number, because the mean of its divisors is an integer number (2952720).

Almost surely, 2^21379489 is an apocalyptic number.

It is an amenable number.

21379489 is a deficient number, since it is larger than the sum of its proper divisors (2242271).

21379489 is a wasteful number, since it uses less digits than its factorization.

21379489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54719.

The product of its digits is 108864, while the sum is 43.

The square root of 21379489 is about 4623.7959513802. The cubic root of 21379489 is about 277.5443816145.

The spelling of 21379489 in words is "twenty-one million, three hundred seventy-nine thousand, four hundred eighty-nine".