2157783265620 has 36 divisors (see below), whose sum is σ = 6545275906260. Its totient is φ = 575408870784.

The previous prime is 2157783265619. The next prime is 2157783265621. The reversal of 2157783265620 is 265623877512.

2157783265620 is a `hidden beast` number, since 2 + 1 + 5 + 7 + 7 + 8 + 3 + 2 + 6 + 5 + 620 = 666.

It is an interprime number because it is at equal distance from previous prime (2157783265619) and next prime (2157783265621).

It can be written as a sum of positive squares in 2 ways, for example, as 1704795039684 + 452988225936 = 1305678^2 + 673044^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×2157783265620² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157783265621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5993842225 + ... + 5993842584.

Almost surely, 2^{2157783265620} is an apocalyptic number.

2157783265620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2157783265620 is an abundant number, since it is smaller than the sum of its proper divisors (4387492640640).

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

2157783265620 is a wasteful number, since it uses less digits than its factorization.

2157783265620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11987684824 (or 11987684819 counting only the distinct ones).

The product of its (nonzero) digits is 8467200, while the sum is 54.

The spelling of 2157783265620 in words is "two trillion, one hundred fifty-seven billion, seven hundred eighty-three million, two hundred sixty-five thousand, six hundred twenty".