2157555440 has 40 divisors (see below), whose sum is σ = 5091199440. Its totient is φ = 850139136.

The previous prime is 2157555403. The next prime is 2157555473. The reversal of 2157555440 is 445557512.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 2157555394 and 2157555403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195905 + ... + 206624.

It is an arithmetic number, because the mean of its divisors is an integer number (127279986).

Almost surely, 2^2157555440 is an apocalyptic number.

2157555440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2157555440 is an abundant number, since it is smaller than the sum of its proper divisors (2933644000).

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

2157555440 is a wasteful number, since it uses less digits than its factorization.

2157555440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402609 (or 402603 counting only the distinct ones).

The product of its (nonzero) digits is 140000, while the sum is 38.

The square root of 2157555440 is about 46449.4934310375. The cubic root of 2157555440 is about 1292.1729776357.

The spelling of 2157555440 in words is "two billion, one hundred fifty-seven million, five hundred fifty-five thousand, four hundred forty".