20087257 has 4 divisors (see below), whose sum is σ = 20960640. Its totient is φ = 19213876.

The previous prime is 20087231. The next prime is 20087269. The reversal of 20087257 is 75278002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20087257 - 2¹¹ = 20085209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20087357) 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 3 ways as a sum of consecutive naturals, for example, 436657 + ... + 436702.

It is an arithmetic number, because the mean of its divisors is an integer number (5240160).

Almost surely, 2^20087257 is an apocalyptic number.

It is an amenable number.

20087257 is a deficient number, since it is larger than the sum of its proper divisors (873383).

20087257 is an equidigital number, since it uses as much as digits as its factorization.

20087257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873382.

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 20087257 is about 4481.8809667371. The cubic root of 20087257 is about 271.8359421938.

The spelling of 20087257 in words is "twenty million, eighty-seven thousand, two hundred fifty-seven".