2154021243 has 16 divisors (see below), whose sum is σ = 3164147712. Its totient is φ = 1292540000.

The previous prime is 2154021211. The next prime is 2154021251. The reversal of 2154021243 is 3421204512.

It is a cyclic number.

It is not a de Polignac number, because 2154021243 - 2⁵ = 2154021211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2154021253) 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, 319803 + ... + 326468.

It is an arithmetic number, because the mean of its divisors is an integer number (197759232).

Almost surely, 2^2154021243 is an apocalyptic number.

2154021243 is a deficient number, since it is larger than the sum of its proper divisors (1010126469).

2154021243 is a wasteful number, since it uses less digits than its factorization.

2154021243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646386.

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 2154021243 is about 46411.4343992943. The cubic root of 2154021243 is about 1291.4670414014.

Adding to 2154021243 its reverse (3421204512), we get a palindrome (5575225755).

The spelling of 2154021243 in words is "two billion, one hundred fifty-four million, twenty-one thousand, two hundred forty-three".