21312153452 has 24 divisors (see below), whose sum is σ = 37593871392. Its totient is φ = 10571385600.

The previous prime is 21312153437. The next prime is 21312153469. The reversal of 21312153452 is 25435121312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211502 + ... + 295562.

It is an arithmetic number, because the mean of its divisors is an integer number (1566411308).

Almost surely, 2^21312153452 is an apocalyptic number.

It is an amenable number.

21312153452 is a deficient number, since it is larger than the sum of its proper divisors (16281717940).

21312153452 is a wasteful number, since it uses less digits than its factorization.

21312153452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84569 (or 84567 counting only the distinct ones).

The product of its digits is 7200, while the sum is 29.

Adding to 21312153452 its reverse (25435121312), we get a palindrome (46747274764).

The spelling of 21312153452 in words is "twenty-one billion, three hundred twelve million, one hundred fifty-three thousand, four hundred fifty-two".