21594149 has 2 divisors, whose sum is σ = 21594150. Its totient is φ = 21594148.

The previous prime is 21594137. The next prime is 21594169. The reversal of 21594149 is 94149512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13653025 + 7941124 = 3695^2 + 2818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21594149 - 2²⁰ = 20545573 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21594169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10797074 + 10797075.

It is an arithmetic number, because the mean of its divisors is an integer number (10797075).

Almost surely, 2^21594149 is an apocalyptic number.

It is an amenable number.

21594149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21594149 is an equidigital number, since it uses as much as digits as its factorization.

21594149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 35.

The square root of 21594149 is about 4646.9505054390. The cubic root of 21594149 is about 278.4701815086.

The spelling of 21594149 in words is "twenty-one million, five hundred ninety-four thousand, one hundred forty-nine".