20731669 has 4 divisors (see below), whose sum is σ = 23693344. Its totient is φ = 17769996.

The previous prime is 20731663. The next prime is 20731681. The reversal of 20731669 is 96613702.

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, and also an emirpimes, since its reverse is a distinct semiprime: 96613702 = 2 ⋅48306851.

It is a cyclic number.

It is not a de Polignac number, because 20731669 - 2⁵ = 20731637 is a prime.

It is a super-2 number, since 2×20731669² = 859604199051122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731663) 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, 1480827 + ... + 1480840.

It is an arithmetic number, because the mean of its divisors is an integer number (5923336).

Almost surely, 2^20731669 is an apocalyptic number.

It is an amenable number.

20731669 is a deficient number, since it is larger than the sum of its proper divisors (2961675).

20731669 is an equidigital number, since it uses as much as digits as its factorization.

20731669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2961674.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20731669 is about 4553.2042563452. The cubic root of 20731669 is about 274.7122897306.

The spelling of 20731669 in words is "twenty million, seven hundred thirty-one thousand, six hundred sixty-nine".