21326961 has 8 divisors (see below), whose sum is σ = 28476544. Its totient is φ = 14197680.

The previous prime is 21326953. The next prime is 21326989. The reversal of 21326961 is 16962312.

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

It is not a de Polignac number, because 21326961 - 2³ = 21326953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21326941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2425 + ... + 6966.

It is an arithmetic number, because the mean of its divisors is an integer number (3559568).

Almost surely, 2^21326961 is an apocalyptic number.

It is an amenable number.

21326961 is a deficient number, since it is larger than the sum of its proper divisors (7149583).

21326961 is an equidigital number, since it uses as much as digits as its factorization.

21326961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10151.

The product of its digits is 3888, while the sum is 30.

The square root of 21326961 is about 4618.1122766776. The cubic root of 21326961 is about 277.3168924330.

The spelling of 21326961 in words is "twenty-one million, three hundred twenty-six thousand, nine hundred sixty-one".