20425566 has 16 divisors (see below), whose sum is σ = 46687104. Its totient is φ = 5835864.

The previous prime is 20425549. The next prime is 20425571. The reversal of 20425566 is 66552402.

20425566 = T₂₇₀ + T₂₇₁ + ... + T₅₂₁.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 243120 + ... + 243203.

It is an arithmetic number, because the mean of its divisors is an integer number (2917944).

Almost surely, 2^20425566 is an apocalyptic number.

20425566 is an abundant number, since it is smaller than the sum of its proper divisors (26261538).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20425566 is a wasteful number, since it uses less digits than its factorization.

20425566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486335.

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 20425566 is about 4519.4652338523. The cubic root of 20425566 is about 273.3535383967.

Adding to 20425566 its reverse (66552402), we get a palindrome (86977968).

The spelling of 20425566 in words is "twenty million, four hundred twenty-five thousand, five hundred sixty-six".