20597261 has 4 divisors (see below), whose sum is σ = 20754624. Its totient is φ = 20439900.

The previous prime is 20597209. The next prime is 20597267. The reversal of 20597261 is 16279502.

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 a de Polignac number, because none of the positive numbers 2^k-20597261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20597267) 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, 78485 + ... + 78746.

It is an arithmetic number, because the mean of its divisors is an integer number (5188656).

Almost surely, 2^20597261 is an apocalyptic number.

It is an amenable number.

20597261 is a deficient number, since it is larger than the sum of its proper divisors (157363).

20597261 is a wasteful number, since it uses less digits than its factorization.

20597261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157362.

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

The square root of 20597261 is about 4538.4205402320. The cubic root of 20597261 is about 274.1173285859.

The spelling of 20597261 in words is "twenty million, five hundred ninety-seven thousand, two hundred sixty-one".