20425457 has 4 divisors (see below), whose sum is σ = 21996660. Its totient is φ = 18854256.

The previous prime is 20425451. The next prime is 20425477. The reversal of 20425457 is 75452402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75452402 = 2 ⋅37726201.

It can be written as a sum of positive squares in 2 ways, for example, as 2819041 + 17606416 = 1679^2 + 4196^2 .

It is a cyclic number.

It is not a de Polignac number, because 20425457 - 2²⁰ = 19376881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20425451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785582 + ... + 785607.

It is an arithmetic number, because the mean of its divisors is an integer number (5499165).

Almost surely, 2^20425457 is an apocalyptic number.

It is an amenable number.

20425457 is a deficient number, since it is larger than the sum of its proper divisors (1571203).

20425457 is a wasteful number, since it uses less digits than its factorization.

20425457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571202.

The product of its (nonzero) digits is 11200, while the sum is 29.

The square root of 20425457 is about 4519.4531748874. The cubic root of 20425457 is about 273.3530521500.

Adding to 20425457 its reverse (75452402), we get a palindrome (95877859).

The spelling of 20425457 in words is "twenty million, four hundred twenty-five thousand, four hundred fifty-seven".