20646461 has 4 divisors (see below), whose sum is σ = 22523424. Its totient is φ = 18769500.

The previous prime is 20646443. The next prime is 20646467. The reversal of 20646461 is 16464602.

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 20646461 - 2¹⁸ = 20384317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20646467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 938465 + ... + 938486.

It is an arithmetic number, because the mean of its divisors is an integer number (5630856).

Almost surely, 2^20646461 is an apocalyptic number.

It is an amenable number.

20646461 is a deficient number, since it is larger than the sum of its proper divisors (1876963).

20646461 is a wasteful number, since it uses less digits than its factorization.

20646461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1876962.

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 20646461 is about 4543.8376951647. The cubic root of 20646461 is about 274.3354133834.

The spelling of 20646461 in words is "twenty million, six hundred forty-six thousand, four hundred sixty-one".