21452401564 has 12 divisors (see below), whose sum is σ = 40954584888. Its totient is φ = 9751091600.

The previous prime is 21452401519. The next prime is 21452401577. The reversal of 21452401564 is 46510425412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243777247 + ... + 243777334.

It is an arithmetic number, because the mean of its divisors is an integer number (3412882074).

Almost surely, 2^21452401564 is an apocalyptic number.

It is an amenable number.

21452401564 is a deficient number, since it is larger than the sum of its proper divisors (19502183324).

21452401564 is a wasteful number, since it uses less digits than its factorization.

21452401564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487554596 (or 487554594 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 34.

Adding to 21452401564 its reverse (46510425412), we get a palindrome (67962826976).

The spelling of 21452401564 in words is "twenty-one billion, four hundred fifty-two million, four hundred one thousand, five hundred sixty-four".