20800457 has 4 divisors (see below), whose sum is σ = 21034260. Its totient is φ = 20566656.

The previous prime is 20800427. The next prime is 20800471. The reversal of 20800457 is 75400802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75400802 = 2 ⋅37700401.

It can be written as a sum of positive squares in 2 ways, for example, as 5621641 + 15178816 = 2371^2 + 3896^2 .

It is a cyclic number.

It is not a de Polignac number, because 20800457 - 2⁶ = 20800393 is a prime.

It is a super-2 number, since 2×20800457² = 865318022817698, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20800427) 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, 116768 + ... + 116945.

It is an arithmetic number, because the mean of its divisors is an integer number (5258565).

Almost surely, 2^20800457 is an apocalyptic number.

It is an amenable number.

20800457 is a deficient number, since it is larger than the sum of its proper divisors (233803).

20800457 is an equidigital number, since it uses as much as digits as its factorization.

20800457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233802.

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 20800457 is about 4560.7518020607. The cubic root of 20800457 is about 275.0157875234.

The spelling of 20800457 in words is "twenty million, eight hundred thousand, four hundred fifty-seven".