2123561440 has 192 divisors, whose sum is σ = 6736504320. Its totient is φ = 610928640.

The previous prime is 2123561393. The next prime is 2123561491. The reversal of 2123561440 is 441653212.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 2123561399 and 2123561408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 153531 + ... + 166789.

It is an arithmetic number, because the mean of its divisors is an integer number (35085960).

Almost surely, 2^2123561440 is an apocalyptic number.

2123561440 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 2123561440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3368252160).

2123561440 is an abundant number, since it is smaller than the sum of its proper divisors (4612942880).

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

2123561440 is a wasteful number, since it uses less digits than its factorization.

2123561440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13305 (or 13297 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 2123561440 is about 46082.1162708485. The cubic root of 2123561440 is about 1285.3506166743.

The spelling of 2123561440 in words is "two billion, one hundred twenty-three million, five hundred sixty-one thousand, four hundred forty".