21574901 has 2 divisors, whose sum is σ = 21574902. Its totient is φ = 21574900.

The previous prime is 21574879. The next prime is 21574909. The reversal of 21574901 is 10947512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21298225 + 276676 = 4615^2 + 526^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21574901 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21574909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10787450 + 10787451.

It is an arithmetic number, because the mean of its divisors is an integer number (10787451).

Almost surely, 2^21574901 is an apocalyptic number.

It is an amenable number.

21574901 is a deficient number, since it is larger than the sum of its proper divisors (1).

21574901 is an equidigital number, since it uses as much as digits as its factorization.

21574901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 21574901 is about 4644.8790081121. The cubic root of 21574901 is about 278.3874185437.

The spelling of 21574901 in words is "twenty-one million, five hundred seventy-four thousand, nine hundred one".