21151049 has 2 divisors, whose sum is σ = 21151050. Its totient is φ = 21151048.

The previous prime is 21151027. The next prime is 21151057. The reversal of 21151049 is 94015112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16605625 + 4545424 = 4075^2 + 2132^2 .

It is a cyclic number.

It is not a de Polignac number, because 21151049 - 2¹² = 21146953 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21151069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575524 + 10575525.

It is an arithmetic number, because the mean of its divisors is an integer number (10575525).

Almost surely, 2^21151049 is an apocalyptic number.

It is an amenable number.

21151049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21151049 is an equidigital number, since it uses as much as digits as its factorization.

21151049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 21151049 is about 4599.0269623041. The cubic root of 21151049 is about 276.5523185140.

The spelling of 21151049 in words is "twenty-one million, one hundred fifty-one thousand, forty-nine".