20257633 has 4 divisors (see below), whose sum is σ = 22099248. Its totient is φ = 18416020.

The previous prime is 20257621. The next prime is 20257669. The reversal of 20257633 is 33675202.

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 20257633 - 2⁹ = 20257121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20257613) 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, 920791 + ... + 920812.

It is an arithmetic number, because the mean of its divisors is an integer number (5524812).

Almost surely, 2^20257633 is an apocalyptic number.

It is an amenable number.

20257633 is a deficient number, since it is larger than the sum of its proper divisors (1841615).

20257633 is a wasteful number, since it uses less digits than its factorization.

20257633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1841614.

The product of its (nonzero) digits is 7560, while the sum is 28.

The square root of 20257633 is about 4500.8480312048. The cubic root of 20257633 is about 272.6023317375.

Subtracting 20257633 from its reverse (33675202), we obtain a square (13417569 = 3663²).

The spelling of 20257633 in words is "twenty million, two hundred fifty-seven thousand, six hundred thirty-three".