20380491 has 10 divisors (see below), whose sum is σ = 30445052. Its totient is φ = 13586940.

The previous prime is 20380489. The next prime is 20380537. The reversal of 20380491 is 19408302.

It is not a de Polignac number, because 20380491 - 2¹ = 20380489 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20380471) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 125725 + ... + 125886.

Almost surely, 2^20380491 is an apocalyptic number.

20380491 is a deficient number, since it is larger than the sum of its proper divisors (10064561).

20380491 is an equidigital number, since it uses as much as digits as its factorization.

20380491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251623 (or 251614 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20380491 is about 4514.4757170684. The cubic root of 20380491 is about 273.1523120598.

Adding to 20380491 its reverse (19408302), we get a palindrome (39788793).

The spelling of 20380491 in words is "twenty million, three hundred eighty thousand, four hundred ninety-one".