21153995 has 8 divisors (see below), whose sum is σ = 25925184. Its totient is φ = 16562944.

The previous prime is 21153971. The next prime is 21154019. The reversal of 21153995 is 59935112.

It is an interprime number because it is at equal distance from previous prime (21153971) and next prime (21154019).

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 21153995 - 2⁶ = 21153931 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 44774 + ... + 45243.

It is an arithmetic number, because the mean of its divisors is an integer number (3240648).

Almost surely, 2^21153995 is an apocalyptic number.

21153995 is a deficient number, since it is larger than the sum of its proper divisors (4771189).

21153995 is an equidigital number, since it uses as much as digits as its factorization.

21153995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90069.

The product of its digits is 12150, while the sum is 35.

The square root of 21153995 is about 4599.3472362934. The cubic root of 21153995 is about 276.5651576771.

The spelling of 21153995 in words is "twenty-one million, one hundred fifty-three thousand, nine hundred ninety-five".