20405132 has 12 divisors (see below), whose sum is σ = 38955336. Its totient is φ = 9275040.

The previous prime is 20405129. The next prime is 20405137. The reversal of 20405132 is 23150402.

It is a self number, because there is not a number n which added to its sum of digits gives 20405132.

It is not an unprimeable number, because it can be changed into a prime (20405137) 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, 231833 + ... + 231920.

It is an arithmetic number, because the mean of its divisors is an integer number (3246278).

Almost surely, 2^20405132 is an apocalyptic number.

20405132 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

20405132 is a deficient number, since it is larger than the sum of its proper divisors (18550204).

20405132 is a wasteful number, since it uses less digits than its factorization.

20405132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463768 (or 463766 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20405132 is about 4517.2040024776. The cubic root of 20405132 is about 273.2623525121.

Adding to 20405132 its reverse (23150402), we get a palindrome (43555534).

The spelling of 20405132 in words is "twenty million, four hundred five thousand, one hundred thirty-two".