20911023 has 12 divisors (see below), whose sum is σ = 34519888. Its totient is φ = 11949120.

The previous prime is 20910977. The next prime is 20911027. The reversal of 20911023 is 32011902.

It is a happy number.

It is not a de Polignac number, because 20911023 - 2²⁴ = 4133807 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20910987 and 20911005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20911027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165898 + ... + 166023.

Almost surely, 2^20911023 is an apocalyptic number.

20911023 is a deficient number, since it is larger than the sum of its proper divisors (13608865).

20911023 is a wasteful number, since it uses less digits than its factorization.

20911023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331934 (or 331931 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 20911023 is about 4572.8572031062. The cubic root of 20911023 is about 275.5022139626.

Adding to 20911023 its reverse (32011902), we get a palindrome (52922925).

The spelling of 20911023 in words is "twenty million, nine hundred eleven thousand, twenty-three".