2154431021 has 8 divisors (see below), whose sum is σ = 2209082304. Its totient is φ = 2099986560.

The previous prime is 2154431009. The next prime is 2154431023. The reversal of 2154431021 is 1201344512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2154431021 - 2¹⁴ = 2154414637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2154431023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30500 + ... + 72381.

It is an arithmetic number, because the mean of its divisors is an integer number (276135288).

Almost surely, 2^2154431021 is an apocalyptic number.

It is an amenable number.

2154431021 is a deficient number, since it is larger than the sum of its proper divisors (54651283).

2154431021 is a wasteful number, since it uses less digits than its factorization.

2154431021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103411.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 2154431021 is about 46415.8488126631. The cubic root of 2154431021 is about 1291.5489318389.

Adding to 2154431021 its reverse (1201344512), we get a palindrome (3355775533).

The spelling of 2154431021 in words is "two billion, one hundred fifty-four million, four hundred thirty-one thousand, twenty-one".