21736619 has 2 divisors, whose sum is σ = 21736620. Its totient is φ = 21736618.

The previous prime is 21736597. The next prime is 21736657. The reversal of 21736619 is 91663712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21736619 - 2²⁰ = 20688043 is a prime.

It is a super-2 number, since 2×21736619² = 944961211102322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21736669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10868309 + 10868310.

It is an arithmetic number, because the mean of its divisors is an integer number (10868310).

Almost surely, 2^21736619 is an apocalyptic number.

21736619 is a deficient number, since it is larger than the sum of its proper divisors (1).

21736619 is an equidigital number, since it uses as much as digits as its factorization.

21736619 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 35.

The square root of 21736619 is about 4662.2547120465. The cubic root of 21736619 is about 279.0812531251.

The spelling of 21736619 in words is "twenty-one million, seven hundred thirty-six thousand, six hundred nineteen".