20643371 has 8 divisors (see below), whose sum is σ = 23735040. Its totient is φ = 17587368.

The previous prime is 20643353. The next prime is 20643379. The reversal of 20643371 is 17334602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20643371 is a prime.

It is a super-2 number, since 2×20643371² = 852297532487282, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20643371.

It is not an unprimeable number, because it can be changed into a prime (20643379) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7661 + ... + 9998.

It is an arithmetic number, because the mean of its divisors is an integer number (2966880).

Almost surely, 2^20643371 is an apocalyptic number.

20643371 is a deficient number, since it is larger than the sum of its proper divisors (3091669).

20643371 is a wasteful number, since it uses less digits than its factorization.

20643371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17833.

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 20643371 is about 4543.4976614938. The cubic root of 20643371 is about 274.3217267969.

Adding to 20643371 its reverse (17334602), we get a palindrome (37977973).

The spelling of 20643371 in words is "twenty million, six hundred forty-three thousand, three hundred seventy-one".