21233231646 has 32 divisors (see below), whose sum is σ = 46372929408. Its totient is φ = 6427940640.

The previous prime is 21233231599. The next prime is 21233231653. The reversal of 21233231646 is 64613233212.

It is a happy number.

It is a super-2 number, since 2×21233231646² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91936 + ... + 225651.

It is an arithmetic number, because the mean of its divisors is an integer number (1449154044).

Almost surely, 2^21233231646 is an apocalyptic number.

21233231646 is an abundant number, since it is smaller than the sum of its proper divisors (25139697762).

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

21233231646 is a wasteful number, since it uses less digits than its factorization.

21233231646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318616.

The product of its digits is 31104, while the sum is 33.

Adding to 21233231646 its reverse (64613233212), we get a palindrome (85846464858).

The spelling of 21233231646 in words is "twenty-one billion, two hundred thirty-three million, two hundred thirty-one thousand, six hundred forty-six".