21154312452 has 48 divisors (see below), whose sum is σ = 60750849152. Its totient is φ = 5579159040.

The previous prime is 21154312451. The next prime is 21154312483. The reversal of 21154312452 is 25421345112.

It is not an unprimeable number, because it can be changed into a prime (21154312451) 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, 9684949 + ... + 9687132.

Almost surely, 2^21154312452 is an apocalyptic number.

It is an amenable number.

21154312452 is an abundant number, since it is smaller than the sum of its proper divisors (39596536700).

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

21154312452 is a wasteful number, since it uses less digits than its factorization.

21154312452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19372108 (or 19372106 counting only the distinct ones).

The product of its digits is 9600, while the sum is 30.

Adding to 21154312452 its reverse (25421345112), we get a palindrome (46575657564).

The spelling of 21154312452 in words is "twenty-one billion, one hundred fifty-four million, three hundred twelve thousand, four hundred fifty-two".