21363915 has 8 divisors (see below), whose sum is σ = 34182288. Its totient is φ = 11394080.

The previous prime is 21363907. The next prime is 21363949. The reversal of 21363915 is 51936312.

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

It is not a de Polignac number, because 21363915 - 2³ = 21363907 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 712116 + ... + 712145.

It is an arithmetic number, because the mean of its divisors is an integer number (4272786).

Almost surely, 2^21363915 is an apocalyptic number.

21363915 is a deficient number, since it is larger than the sum of its proper divisors (12818373).

21363915 is a wasteful number, since it uses less digits than its factorization.

21363915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1424269.

The product of its digits is 4860, while the sum is 30.

The square root of 21363915 is about 4622.1115304588. Note that the first 3 decimals coincide. The cubic root of 21363915 is about 277.4769723607.

The spelling of 21363915 in words is "twenty-one million, three hundred sixty-three thousand, nine hundred fifteen".