20492921 has 2 divisors, whose sum is σ = 20492922. Its totient is φ = 20492920.

The previous prime is 20492911. The next prime is 20492929. The reversal of 20492921 is 12929402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14167696 + 6325225 = 3764^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 20492921 - 2¹⁰ = 20491897 is a prime.

It is a super-2 number, since 2×20492921² = 839919622224482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20492929) 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, 10246460 + 10246461.

It is an arithmetic number, because the mean of its divisors is an integer number (10246461).

Almost surely, 2^20492921 is an apocalyptic number.

It is an amenable number.

20492921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20492921 is an equidigital number, since it uses as much as digits as its factorization.

20492921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 20492921 is about 4526.9107567965. The cubic root of 20492921 is about 273.6536773909.

The spelling of 20492921 in words is "twenty million, four hundred ninety-two thousand, nine hundred twenty-one".