2157806740 has 24 divisors (see below), whose sum is σ = 4575392640. Its totient is φ = 854742048.

The previous prime is 2157806731. The next prime is 2157806743. The reversal of 2157806740 is 476087512.

It is a super-2 number, since 2×2157806740² = 9312259854378855200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2157806693 and 2157806702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157806743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521680 + ... + 525799.

It is an arithmetic number, because the mean of its divisors is an integer number (190641360).

Almost surely, 2^2157806740 is an apocalyptic number.

2157806740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2157806740 is an abundant number, since it is smaller than the sum of its proper divisors (2417585900).

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

2157806740 is a wasteful number, since it uses less digits than its factorization.

2157806740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1047591 (or 1047589 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 40.

The square root of 2157806740 is about 46452.1984409780. The cubic root of 2157806740 is about 1292.2231440503.

The spelling of 2157806740 in words is "two billion, one hundred fifty-seven million, eight hundred six thousand, seven hundred forty".