2051221640 has 64 divisors (see below), whose sum is σ = 5130639360. Its totient is φ = 732936960.

The previous prime is 2051221637. The next prime is 2051221643. The reversal of 2051221640 is 461221502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2051221637) and next prime (2051221643).

It is not an unprimeable number, because it can be changed into a prime (2051221643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47504 + ... + 79743.

It is an arithmetic number, because the mean of its divisors is an integer number (80166240).

Almost surely, 2^2051221640 is an apocalyptic number.

2051221640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2051221640 is an abundant number, since it is smaller than the sum of its proper divisors (3079417720).

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

2051221640 is a wasteful number, since it uses less digits than its factorization.

2051221640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127302 (or 127298 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 2051221640 is about 45290.4144383776. The cubic root of 2051221640 is about 1270.5863826545.

The spelling of 2051221640 in words is "two billion, fifty-one million, two hundred twenty-one thousand, six hundred forty".