21274949 has 2 divisors, whose sum is σ = 21274950. Its totient is φ = 21274948.

The previous prime is 21274933. The next prime is 21274961. The reversal of 21274949 is 94947212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12124324 + 9150625 = 3482^2 + 3025^2 .

It is a cyclic number.

It is not a de Polignac number, because 21274949 - 2⁴ = 21274933 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21274999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10637474 + 10637475.

It is an arithmetic number, because the mean of its divisors is an integer number (10637475).

Almost surely, 2^21274949 is an apocalyptic number.

It is an amenable number.

21274949 is a deficient number, since it is larger than the sum of its proper divisors (1).

21274949 is an equidigital number, since it uses as much as digits as its factorization.

21274949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 38.

The square root of 21274949 is about 4612.4775338206. The cubic root of 21274949 is about 277.0912696064.

The spelling of 21274949 in words is "twenty-one million, two hundred seventy-four thousand, nine hundred forty-nine".