21596951 has 2 divisors, whose sum is σ = 21596952. Its totient is φ = 21596950.

The previous prime is 21596921. The next prime is 21596959. The reversal of 21596951 is 15969512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21596951 - 2¹⁰ = 21595927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21596959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10798475 + 10798476.

It is an arithmetic number, because the mean of its divisors is an integer number (10798476).

Almost surely, 2^21596951 is an apocalyptic number.

21596951 is a deficient number, since it is larger than the sum of its proper divisors (1).

21596951 is an equidigital number, since it uses as much as digits as its factorization.

21596951 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24300, while the sum is 38.

The square root of 21596951 is about 4647.2519836996. The cubic root of 21596951 is about 278.4822255072.

The spelling of 21596951 in words is "twenty-one million, five hundred ninety-six thousand, nine hundred fifty-one".