21253332534 has 64 divisors (see below), whose sum is σ = 48893952000. Its totient is φ = 6033110688.

The previous prime is 21253332533. The next prime is 21253332539. The reversal of 21253332534 is 43523335212.

It is a super-2 number, since 2×21253332534² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21253332495 and 21253332504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253332533) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7679619 + ... + 7682385.

It is an arithmetic number, because the mean of its divisors is an integer number (763968000).

Almost surely, 2^21253332534 is an apocalyptic number.

21253332534 is an abundant number, since it is smaller than the sum of its proper divisors (27640619466).

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

21253332534 is a wasteful number, since it uses less digits than its factorization.

21253332534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3897.

The product of its digits is 64800, while the sum is 33.

Adding to 21253332534 its reverse (43523335212), we get a palindrome (64776667746).

The spelling of 21253332534 in words is "twenty-one billion, two hundred fifty-three million, three hundred thirty-two thousand, five hundred thirty-four".