2121451020 has 192 divisors, whose sum is σ = 7143776640. Its totient is φ = 519561216.

The previous prime is 2121451019. The next prime is 2121451027. The reversal of 2121451020 is 201541212.

2121451020 is a `hidden beast` number, since 212 + 1 + 451 + 0 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 2121450984 and 2121451002.

It is not an unprimeable number, because it can be changed into a prime (2121451027) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1635012 + ... + 1636308.

It is an arithmetic number, because the mean of its divisors is an integer number (37207170).

Almost surely, 2^2121451020 is an apocalyptic number.

2121451020 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 2121451020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3571888320).

2121451020 is an abundant number, since it is smaller than the sum of its proper divisors (5022325620).

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

2121451020 is a wasteful number, since it uses less digits than its factorization.

2121451020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561 (or 1553 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 2121451020 is about 46059.2121078943. The cubic root of 2121451020 is about 1284.9246767559.

Adding to 2121451020 its reverse (201541212), we get a palindrome (2322992232).

The spelling of 2121451020 in words is "two billion, one hundred twenty-one million, four hundred fifty-one thousand, twenty".