21463221064 has 8 divisors (see below), whose sum is σ = 40243539510. Its totient is φ = 10731610528.

The previous prime is 21463221053. The next prime is 21463221067. The reversal of 21463221064 is 46012236412.

It can be written as a sum of positive squares in only one way, i.e., 18132776964 + 3330444100 = 134658^2 + 57710^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21463221067) by changing a digit.

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 as a sum of consecutive naturals, namely, 1341451309 + ... + 1341451324.

Almost surely, 2^21463221064 is an apocalyptic number.

It is an amenable number.

21463221064 is a deficient number, since it is larger than the sum of its proper divisors (18780318446).

21463221064 is a wasteful number, since it uses less digits than its factorization.

21463221064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2682902639 (or 2682902635 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 31.

Adding to 21463221064 its reverse (46012236412), we get a palindrome (67475457476).

The spelling of 21463221064 in words is "twenty-one billion, four hundred sixty-three million, two hundred twenty-one thousand, sixty-four".