20149021 has 2 divisors, whose sum is σ = 20149022. Its totient is φ = 20149020.

The previous prime is 20149013. The next prime is 20149027. The reversal of 20149021 is 12094102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19236996 + 912025 = 4386^2 + 955^2 .

It is a cyclic number.

It is not a de Polignac number, because 20149021 - 2³ = 20149013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20149021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20149027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10074510 + 10074511.

It is an arithmetic number, because the mean of its divisors is an integer number (10074511).

Almost surely, 2^20149021 is an apocalyptic number.

It is an amenable number.

20149021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20149021 is an equidigital number, since it uses as much as digits as its factorization.

20149021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 20149021 is about 4488.7660888044. The cubic root of 20149021 is about 272.1142694978.

The spelling of 20149021 in words is "twenty million, one hundred forty-nine thousand, twenty-one".