21535450531 has 8 divisors (see below), whose sum is σ = 25212235104. Its totient is φ = 18008738880.

The previous prime is 21535450493. The next prime is 21535450549. The reversal of 21535450531 is 13505453512.

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 21535450531 - 2⁷ = 21535450403 is a prime.

It is a super-2 number, since 2×21535450531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21535450571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37517920 + ... + 37518493.

It is an arithmetic number, because the mean of its divisors is an integer number (3151529388).

Almost surely, 2^21535450531 is an apocalyptic number.

21535450531 is a deficient number, since it is larger than the sum of its proper divisors (3676784573).

21535450531 is an equidigital number, since it uses as much as digits as its factorization.

21535450531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75036461.

The product of its (nonzero) digits is 45000, while the sum is 34.

The spelling of 21535450531 in words is "twenty-one billion, five hundred thirty-five million, four hundred fifty thousand, five hundred thirty-one".