20457081 has 12 divisors (see below), whose sum is σ = 29657940. Its totient is φ = 13587840.

The previous prime is 20457067. The next prime is 20457119. The reversal of 20457081 is 18075402.

It can be written as a sum of positive squares in 2 ways, for example, as 5363856 + 15093225 = 2316^2 + 3885^2 .

It is not a de Polignac number, because 20457081 - 2⁵ = 20457049 is a prime.

It is a super-2 number, since 2×20457081² = 836984326081122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20455081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1516 + ... + 6573.

It is an arithmetic number, because the mean of its divisors is an integer number (2471495).

Almost surely, 2^20457081 is an apocalyptic number.

It is an amenable number.

20457081 is a deficient number, since it is larger than the sum of its proper divisors (9200859).

20457081 is a wasteful number, since it uses less digits than its factorization.

20457081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8376 (or 8373 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20457081 is about 4522.9504750771. The cubic root of 20457081 is about 273.4940536369.

The spelling of 20457081 in words is "twenty million, four hundred fifty-seven thousand, eighty-one".