20400102 has 48 divisors (see below), whose sum is σ = 47202480. Its totient is φ = 6345216.

The previous prime is 20400101. The next prime is 20400151. The reversal of 20400102 is 20100402.

It is a super-2 number, since 2×20400102² = 832328323220808, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49674 + ... + 50082.

It is an arithmetic number, because the mean of its divisors is an integer number (983385).

Almost surely, 2^20400102 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20400102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23601240).

20400102 is an abundant number, since it is smaller than the sum of its proper divisors (26802378).

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

20400102 is a wasteful number, since it uses less digits than its factorization.

20400102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597 (or 594 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 20400102 is about 4516.6472078302. The cubic root of 20400102 is about 273.2398970078.

Adding to 20400102 its reverse (20100402), we get a palindrome (40500504).

It can be divided in two parts, 20400 and 102, that added together give a palindrome (20502).

The spelling of 20400102 in words is "twenty million, four hundred thousand, one hundred two".