21400243253 has 8 divisors (see below), whose sum is σ = 21494289600. Its totient is φ = 21306280960.

The previous prime is 21400243213. The next prime is 21400243279. The reversal of 21400243253 is 35234200412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21400243253 is a prime.

It is a super-2 number, since 2×21400243253² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400243213) 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, 519608 + ... + 559278.

It is an arithmetic number, because the mean of its divisors is an integer number (2686786200).

Almost surely, 2^21400243253 is an apocalyptic number.

It is an amenable number.

21400243253 is a deficient number, since it is larger than the sum of its proper divisors (94046347).

21400243253 is a wasteful number, since it uses less digits than its factorization.

21400243253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42027.

The product of its (nonzero) digits is 5760, while the sum is 26.

Adding to 21400243253 its reverse (35234200412), we get a palindrome (56634443665).

The spelling of 21400243253 in words is "twenty-one billion, four hundred million, two hundred forty-three thousand, two hundred fifty-three".