21284487253 has 8 divisors (see below), whose sum is σ = 21981236480. Its totient is φ = 20588372640.

The previous prime is 21284487233. The next prime is 21284487283. The reversal of 21284487253 is 35278448212.

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 21284487253 - 2¹³ = 21284479061 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 (21284487223) 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, 90000 + ... + 225097.

It is an arithmetic number, because the mean of its divisors is an integer number (2747654560).

Almost surely, 2^21284487253 is an apocalyptic number.

It is an amenable number.

21284487253 is a deficient number, since it is larger than the sum of its proper divisors (696749227).

21284487253 is a wasteful number, since it uses less digits than its factorization.

21284487253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317307.

The product of its digits is 860160, while the sum is 46.

The spelling of 21284487253 in words is "twenty-one billion, two hundred eighty-four million, four hundred eighty-seven thousand, two hundred fifty-three".