2155736640 has 224 divisors, whose sum is σ = 7228880640. Its totient is φ = 543195136.

The previous prime is 2155736593. The next prime is 2155736641. The reversal of 2155736640 is 466375512.

It is a super-2 number, since 2×2155736640² = 9294400922076979200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2155736641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1964572 + ... + 1965668.

Almost surely, 2^2155736640 is an apocalyptic number.

2155736640 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 2155736640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3614440320).

2155736640 is an abundant number, since it is smaller than the sum of its proper divisors (5073144000).

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

2155736640 is a wasteful number, since it uses less digits than its factorization.

2155736640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1229 (or 1219 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 39.

The square root of 2155736640 is about 46429.9110488056. The cubic root of 2155736640 is about 1291.8097787922.

The spelling of 2155736640 in words is "two billion, one hundred fifty-five million, seven hundred thirty-six thousand, six hundred forty".