20257961 has 4 divisors (see below), whose sum is σ = 20291412. Its totient is φ = 20224512.

The previous prime is 20257949. The next prime is 20257997. The reversal of 20257961 is 16975202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5550736 + 14707225 = 2356^2 + 3835^2 .

It is a cyclic number.

It is not a de Polignac number, because 20257961 - 2¹⁰ = 20256937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20257901) 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, 15800 + ... + 17033.

It is an arithmetic number, because the mean of its divisors is an integer number (5072853).

Almost surely, 2^20257961 is an apocalyptic number.

It is an amenable number.

20257961 is a deficient number, since it is larger than the sum of its proper divisors (33451).

20257961 is an equidigital number, since it uses as much as digits as its factorization.

20257961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33450.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 20257961 is about 4500.8844686350. The cubic root of 20257961 is about 272.6038030032.

The spelling of 20257961 in words is "twenty million, two hundred fifty-seven thousand, nine hundred sixty-one".