2129665920 has 128 divisors (see below), whose sum is σ = 7145712000. Its totient is φ = 538011648.

The previous prime is 2129665919. The next prime is 2129665957. The reversal of 2129665920 is 295669212.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7291 + ... + 65669.

It is an arithmetic number, because the mean of its divisors is an integer number (55825875).

Almost surely, 2^2129665920 is an apocalyptic number.

2129665920 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 2129665920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3572856000).

2129665920 is an abundant number, since it is smaller than the sum of its proper divisors (5016046080).

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

2129665920 is a wasteful number, since it uses less digits than its factorization.

2129665920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58420 (or 58408 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 42.

The square root of 2129665920 is about 46148.3035441174. The cubic root of 2129665920 is about 1286.5810795561.

The spelling of 2129665920 in words is "two billion, one hundred twenty-nine million, six hundred sixty-five thousand, nine hundred twenty".