20542499 has 2 divisors, whose sum is σ = 20542500. Its totient is φ = 20542498.

The previous prime is 20542471. The next prime is 20542507. The reversal of 20542499 is 99424502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20542499 - 2¹² = 20538403 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20542099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10271249 + 10271250.

It is an arithmetic number, because the mean of its divisors is an integer number (10271250).

Almost surely, 2^20542499 is an apocalyptic number.

20542499 is a deficient number, since it is larger than the sum of its proper divisors (1).

20542499 is an equidigital number, since it uses as much as digits as its factorization.

20542499 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 20542499 is about 4532.3833686042. The cubic root of 20542499 is about 273.8741807828.

The spelling of 20542499 in words is "twenty million, five hundred forty-two thousand, four hundred ninety-nine".