21479645 has 8 divisors (see below), whose sum is σ = 28118880. Its totient is φ = 15621520.

The previous prime is 21479639. The next prime is 21479657. The reversal of 21479645 is 54697412.

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

It is not a de Polignac number, because 21479645 - 2⁶ = 21479581 is a prime.

It is a super-2 number, since 2×21479645² = 922750298652050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21479599 and 21479608.

It is a congruent number.

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 in 7 ways as a sum of consecutive naturals, for example, 195215 + ... + 195324.

It is an arithmetic number, because the mean of its divisors is an integer number (3514860).

Almost surely, 2^21479645 is an apocalyptic number.

It is an amenable number.

21479645 is a deficient number, since it is larger than the sum of its proper divisors (6639235).

21479645 is a wasteful number, since it uses less digits than its factorization.

21479645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390555.

The product of its digits is 60480, while the sum is 38.

The square root of 21479645 is about 4634.6137918925. The cubic root of 21479645 is about 277.9771085131.

The spelling of 21479645 in words is "twenty-one million, four hundred seventy-nine thousand, six hundred forty-five".