21959151 has 16 divisors (see below), whose sum is σ = 30105600. Its totient is φ = 14231808.

The previous prime is 21959143. The next prime is 21959159. The reversal of 21959151 is 15195912.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21959143) and next prime (21959159).

It is not a de Polignac number, because 21959151 - 2³ = 21959143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21959159) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16530 + ... + 17808.

It is an arithmetic number, because the mean of its divisors is an integer number (1881600).

Almost surely, 2^21959151 is an apocalyptic number.

21959151 is a deficient number, since it is larger than the sum of its proper divisors (8146449).

21959151 is a wasteful number, since it uses less digits than its factorization.

21959151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1438.

The product of its digits is 4050, while the sum is 33.

The square root of 21959151 is about 4686.0592185759. The cubic root of 21959151 is about 280.0304006107.

The spelling of 21959151 in words is "twenty-one million, nine hundred fifty-nine thousand, one hundred fifty-one".