20400402 has 64 divisors (see below), whose sum is σ = 47278080. Its totient is φ = 5808000.

The previous prime is 20400377. The next prime is 20400421.

20400402 is nontrivially palindromic in base 10.

It is an unprimeable number.

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, 135027 + ... + 135177.

It is an arithmetic number, because the mean of its divisors is an integer number (738720).

Almost surely, 2^20400402 is an apocalyptic number.

20400402 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 20400402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23639040).

20400402 is an abundant number, since it is smaller than the sum of its proper divisors (26877678).

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

20400402 is a wasteful number, since it uses less digits than its factorization.

20400402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279.

The product of its (nonzero) digits is 64, while the sum is 12.

The square root of 20400402 is about 4516.6804181832. The cubic root of 20400402 is about 273.2412364058.

It can be divided in two parts, 20400 and 402, that added together give a palindrome (20802).

The spelling of 20400402 in words is "twenty million, four hundred thousand, four hundred two".