20145864 has 32 divisors (see below), whose sum is σ = 50869440. Its totient is φ = 6648000.

The previous prime is 20145863. The next prime is 20145889. The reversal of 20145864 is 46854102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20145863) 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, 1732 + ... + 6579.

It is an arithmetic number, because the mean of its divisors is an integer number (1589670).

Almost surely, 2^20145864 is an apocalyptic number.

20145864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20145864 is an abundant number, since it is smaller than the sum of its proper divisors (30723576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20145864 is a wasteful number, since it uses less digits than its factorization.

20145864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8421 (or 8417 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 20145864 is about 4488.4144193690. The cubic root of 20145864 is about 272.1000569029.

Adding to 20145864 its reverse (46854102), we get a palindrome (66999966).

The spelling of 20145864 in words is "twenty million, one hundred forty-five thousand, eight hundred sixty-four".