2153980921 has 3 divisors (see below), whose sum is σ = 2154027333. Its totient is φ = 2153934510.

The previous prime is 2153980877. The next prime is 2153980949. The reversal of 2153980921 is 1290893512.

The square root of 2153980921 is 46411.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 2153980921 - 2⁷ = 2153980793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2153980951) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 23206 + ... + 69616.

It is an arithmetic number, because the mean of its divisors is an integer number (718009111).

Almost surely, 2^2153980921 is an apocalyptic number.

2153980921 is the 46411-st square number.

2153980921 is the 23206-th centered octagonal number.

It is an amenable number.

2153980921 is a deficient number, since it is larger than the sum of its proper divisors (46412).

2153980921 is an frugal number, since it uses more digits than its factorization.

2153980921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92822 (or 46411 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 40.

The cubic root of 2153980921 is about 1291.4589828521.

The spelling of 2153980921 in words is "two billion, one hundred fifty-three million, nine hundred eighty thousand, nine hundred twenty-one".