20662961 has 4 divisors (see below), whose sum is σ = 22541424. Its totient is φ = 18784500.

The previous prime is 20662949. The next prime is 20662969. The reversal of 20662961 is 16926602.

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 20662961 - 2⁶ = 20662897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20662969) 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, 939215 + ... + 939236.

It is an arithmetic number, because the mean of its divisors is an integer number (5635356).

Almost surely, 2^20662961 is an apocalyptic number.

It is an amenable number.

20662961 is a deficient number, since it is larger than the sum of its proper divisors (1878463).

20662961 is a wasteful number, since it uses less digits than its factorization.

20662961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1878462.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 20662961 is about 4545.6529783960. The cubic root of 20662961 is about 274.4084739922.

The spelling of 20662961 in words is "twenty million, six hundred sixty-two thousand, nine hundred sixty-one".