21388046 has 8 divisors (see below), whose sum is σ = 32259864. Its totient is φ = 10634760.

The previous prime is 21388043. The next prime is 21388049. The reversal of 21388046 is 64088312.

It is an interprime number because it is at equal distance from previous prime (21388043) and next prime (21388049).

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21388043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29180 + ... + 29903.

It is an arithmetic number, because the mean of its divisors is an integer number (4032483).

Almost surely, 2^21388046 is an apocalyptic number.

21388046 is a deficient number, since it is larger than the sum of its proper divisors (10871818).

21388046 is a wasteful number, since it uses less digits than its factorization.

21388046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59266.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 21388046 is about 4624.7211807848. The cubic root of 21388046 is about 277.5814051139.

The spelling of 21388046 in words is "twenty-one million, three hundred eighty-eight thousand, forty-six".