2121640251220 has 48 divisors (see below), whose sum is σ = 5359933272960. Its totient is φ = 689134276224.

The previous prime is 2121640251197. The next prime is 2121640251271. The reversal of 2121640251220 is 221520461212.

It is a happy number.

It is a super-2 number, since 2×2121640251220² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

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, 398801899 + ... + 398807218.

It is an arithmetic number, because the mean of its divisors is an integer number (111665276520).

Almost surely, 2^{2121640251220} is an apocalyptic number.

2121640251220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121640251220 is an abundant number, since it is smaller than the sum of its proper divisors (3238293021740).

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

2121640251220 is a wasteful number, since it uses less digits than its factorization.

2121640251220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797609152 (or 797609150 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The spelling of 2121640251220 in words is "two trillion, one hundred twenty-one billion, six hundred forty million, two hundred fifty-one thousand, two hundred twenty".