2355661440 has 640 divisors, whose sum is σ = 9757091520. Its totient is φ = 537477120.

The previous prime is 2355661391. The next prime is 2355661459. The reversal of 2355661440 is 441665532.

2355661440 is a `hidden beast` number, since 2 + 3 + 556 + 61 + 4 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2355661395 and 2355661404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 138568312 + ... + 138568328.

Almost surely, 2^2355661440 is an apocalyptic number.

2355661440 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 2355661440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4878545760).

2355661440 is an abundant number, since it is smaller than the sum of its proper divisors (7401430080).

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

2355661440 is an frugal number, since it uses more digits than its factorization.

2355661440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 2355661440 is about 48535.1567423038. The cubic root of 2355661440 is about 1330.5696845306.

The spelling of 2355661440 in words is "two billion, three hundred fifty-five million, six hundred sixty-one thousand, four hundred forty".