2153721042 has 32 divisors (see below), whose sum is σ = 5221143360. Its totient is φ = 652642560.

The previous prime is 2153720999. The next prime is 2153721043. The reversal of 2153721042 is 2401273512.

2153721042 is a `hidden beast` number, since 21 + 537 + 2 + 104 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 2153720997 and 2153721015.

It is not an unprimeable number, because it can be changed into a prime (2153721043) 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, 1812303 + ... + 1813490.

It is an arithmetic number, because the mean of its divisors is an integer number (163160730).

Almost surely, 2^2153721042 is an apocalyptic number.

2153721042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

2153721042 is an abundant number, since it is smaller than the sum of its proper divisors (3067422318).

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

2153721042 is a wasteful number, since it uses less digits than its factorization.

2153721042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3625815 (or 3625809 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 2153721042 is about 46408.2001590236. The cubic root of 2153721042 is about 1291.4070423475.

Adding to 2153721042 its reverse (2401273512), we get a palindrome (4554994554).

The spelling of 2153721042 in words is "two billion, one hundred fifty-three million, seven hundred twenty-one thousand, forty-two".