20181807 has 12 divisors (see below), whose sum is σ = 29587480. Its totient is φ = 13253328.

The previous prime is 20181803. The next prime is 20181809. The reversal of 20181807 is 70818102.

It is not a de Polignac number, because 20181807 - 2² = 20181803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20181803) 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, 16132 + ... + 17337.

Almost surely, 2^20181807 is an apocalyptic number.

20181807 is a deficient number, since it is larger than the sum of its proper divisors (9405673).

20181807 is a wasteful number, since it uses less digits than its factorization.

20181807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33542 (or 33539 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 20181807 is about 4492.4166102444. The cubic root of 20181807 is about 272.2617821046.

Adding to 20181807 its reverse (70818102), we get a palindrome (90999909).

The spelling of 20181807 in words is "twenty million, one hundred eighty-one thousand, eight hundred seven".