20145940 has 12 divisors (see below), whose sum is σ = 42306516. Its totient is φ = 8058368.

The previous prime is 20145911. The next prime is 20145943. The reversal of 20145940 is 4954102.

It can be written as a sum of positive squares in 2 ways, for example, as 10523536 + 9622404 = 3244^2 + 3102^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20145943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 503629 + ... + 503668.

It is an arithmetic number, because the mean of its divisors is an integer number (3525543).

Almost surely, 2^20145940 is an apocalyptic number.

20145940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20145940 is an abundant number, since it is smaller than the sum of its proper divisors (22160576).

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

20145940 is a wasteful number, since it uses less digits than its factorization.

20145940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007306 (or 1007304 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20145940 is about 4488.4228856025. The cubic root of 20145940 is about 272.1003990671.

The spelling of 20145940 in words is "twenty million, one hundred forty-five thousand, nine hundred forty".