21652691 has 2 divisors, whose sum is σ = 21652692. Its totient is φ = 21652690.

The previous prime is 21652681. The next prime is 21652703. The reversal of 21652691 is 19625612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21652691 - 2¹⁰ = 21651667 is a prime.

It is a super-3 number, since 3×21652691³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21652661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10826345 + 10826346.

It is an arithmetic number, because the mean of its divisors is an integer number (10826346).

Almost surely, 2^21652691 is an apocalyptic number.

21652691 is a deficient number, since it is larger than the sum of its proper divisors (1).

21652691 is an equidigital number, since it uses as much as digits as its factorization.

21652691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 32.

The square root of 21652691 is about 4653.2452116775. The cubic root of 21652691 is about 278.7215997931.

The spelling of 21652691 in words is "twenty-one million, six hundred fifty-two thousand, six hundred ninety-one".