2131223400 has 240 divisors, whose sum is σ = 7443859500. Its totient is φ = 565125120.

The previous prime is 2131223389. The next prime is 2131223473. The reversal of 2131223400 is 43221312.

It can be written as a sum of positive squares in 6 ways, for example, as 1460309796 + 670913604 = 38214^2 + 25902^2 .

It is a super-2 number, since 2×2131223400² = 9084226361415120000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 4746376 + ... + 4746824.

Almost surely, 2^2131223400 is an apocalyptic number.

2131223400 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 2131223400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3721929750).

2131223400 is an abundant number, since it is smaller than the sum of its proper divisors (5312636100).

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

2131223400 is a wasteful number, since it uses less digits than its factorization.

2131223400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770 (or 752 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 2131223400 is about 46165.1751864975. The cubic root of 2131223400 is about 1286.8946398500.

Adding to 2131223400 its reverse (43221312), we get a palindrome (2174444712).

The spelling of 2131223400 in words is "two billion, one hundred thirty-one million, two hundred twenty-three thousand, four hundred".