21389495 has 16 divisors (see below), whose sum is σ = 26574912. Its totient is φ = 16515840.

The previous prime is 21389483. The next prime is 21389503. The reversal of 21389495 is 59498312.

It is not a de Polignac number, because 21389495 - 2⁴ = 21389479 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20609 + ... + 21621.

It is an arithmetic number, because the mean of its divisors is an integer number (1660932).

Almost surely, 2^21389495 is an apocalyptic number.

21389495 is a deficient number, since it is larger than the sum of its proper divisors (5185417).

21389495 is a wasteful number, since it uses less digits than its factorization.

21389495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1162.

The product of its digits is 77760, while the sum is 41.

The square root of 21389495 is about 4624.8778362244. The cubic root of 21389495 is about 277.5876735122.

The spelling of 21389495 in words is "twenty-one million, three hundred eighty-nine thousand, four hundred ninety-five".