20120043400 has 96 divisors (see below), whose sum is σ = 48640581000. Its totient is φ = 7730616320.

The previous prime is 20120043389. The next prime is 20120043413. The reversal of 20120043400 is 434002102.

It can be written as a sum of positive squares in 12 ways, for example, as 8552180484 + 11567862916 = 92478^2 + 107554^2 .

It is a super-2 number, since 2×20120043400² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1133796 + ... + 1151404.

Almost surely, 2^20120043400 is an apocalyptic number.

20120043400 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 20120043400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24320290500).

20120043400 is an abundant number, since it is smaller than the sum of its proper divisors (28520537600).

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

20120043400 is a wasteful number, since it uses less digits than its factorization.

20120043400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17851 (or 17842 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

Adding to 20120043400 its reverse (434002102), we get a palindrome (20554045502).

The spelling of 20120043400 in words is "twenty billion, one hundred twenty million, forty-three thousand, four hundred".