2129771940 has 192 divisors, whose sum is σ = 6706022400. Its totient is φ = 502419456.

The previous prime is 2129771939. The next prime is 2129771971. The reversal of 2129771940 is 491779212.

It is a super-2 number, since 2×2129771940² = 9071857032822727200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2129771892 and 2129771901.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1126516 + ... + 1128404.

It is an arithmetic number, because the mean of its divisors is an integer number (34927200).

Almost surely, 2^2129771940 is an apocalyptic number.

2129771940 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 2129771940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3353011200).

2129771940 is an abundant number, since it is smaller than the sum of its proper divisors (4576250460).

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

2129771940 is a wasteful number, since it uses less digits than its factorization.

2129771940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1986 (or 1984 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 42.

The square root of 2129771940 is about 46149.4522177674. The cubic root of 2129771940 is about 1286.6024289239.

The spelling of 2129771940 in words is "two billion, one hundred twenty-nine million, seven hundred seventy-one thousand, nine hundred forty".