21400432252 has 12 divisors (see below), whose sum is σ = 39653742240. Its totient is φ = 10070791616.

The previous prime is 21400432243. The next prime is 21400432259. The reversal of 21400432252 is 25223400412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400432259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157356052 + ... + 157356187.

It is an arithmetic number, because the mean of its divisors is an integer number (3304478520).

Almost surely, 2^21400432252 is an apocalyptic number.

It is an amenable number.

21400432252 is a deficient number, since it is larger than the sum of its proper divisors (18253309988).

21400432252 is a wasteful number, since it uses less digits than its factorization.

21400432252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314712260 (or 314712258 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21400432252 its reverse (25223400412), we get a palindrome (46623832664).

The spelling of 21400432252 in words is "twenty-one billion, four hundred million, four hundred thirty-two thousand, two hundred fifty-two".