20015457 has 24 divisors (see below), whose sum is σ = 33528768. Its totient is φ = 10396320.

The previous prime is 20015449. The next prime is 20015461. The reversal of 20015457 is 75451002.

It is not a de Polignac number, because 20015457 - 2³ = 20015449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20015447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1398 + ... + 6479.

It is an arithmetic number, because the mean of its divisors is an integer number (1397032).

Almost surely, 2^20015457 is an apocalyptic number.

It is an amenable number.

20015457 is a deficient number, since it is larger than the sum of its proper divisors (13513311).

20015457 is a wasteful number, since it uses less digits than its factorization.

20015457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7909 (or 7898 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 20015457 is about 4473.8637663657. The cubic root of 20015457 is about 271.5116715745.

Adding to 20015457 its reverse (75451002), we get a palindrome (95466459).

The spelling of 20015457 in words is "twenty million, fifteen thousand, four hundred fifty-seven".