21996151 has 2 divisors, whose sum is σ = 21996152. Its totient is φ = 21996150.

The previous prime is 21996127. The next prime is 21996157. The reversal of 21996151 is 15169912.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21996151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21996157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10998075 + 10998076.

It is an arithmetic number, because the mean of its divisors is an integer number (10998076).

Almost surely, 2^21996151 is an apocalyptic number.

21996151 is a deficient number, since it is larger than the sum of its proper divisors (1).

21996151 is an equidigital number, since it uses as much as digits as its factorization.

21996151 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4860, while the sum is 34.

The square root of 21996151 is about 4690.0054370971. The cubic root of 21996151 is about 280.1875911286.

The spelling of 21996151 in words is "twenty-one million, nine hundred ninety-six thousand, one hundred fifty-one".