20402760 has 128 divisors (see below), whose sum is σ = 70917120. Its totient is φ = 4599552.

The previous prime is 20402741. The next prime is 20402761. The reversal of 20402760 is 6720402.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (20402761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89767 + ... + 89993.

It is an arithmetic number, because the mean of its divisors is an integer number (554040).

Almost surely, 2^20402760 is an apocalyptic number.

20402760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20402760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35458560).

20402760 is an abundant number, since it is smaller than the sum of its proper divisors (50514360).

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

20402760 is a wasteful number, since it uses less digits than its factorization.

20402760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 20402760 is about 4516.9414430564. The cubic root of 20402760 is about 273.2517636168.

The spelling of 20402760 in words is "twenty million, four hundred two thousand, seven hundred sixty".