21281238584 has 8 divisors (see below), whose sum is σ = 39902322360. Its totient is φ = 10640619288.

The previous prime is 21281238557. The next prime is 21281238611. The reversal of 21281238584 is 48583218212.

It is an interprime number because it is at equal distance from previous prime (21281238557) and next prime (21281238611).

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

It is a super-2 number, since 2×21281238584² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330077404 + ... + 1330077419.

It is an arithmetic number, because the mean of its divisors is an integer number (4987790295).

Almost surely, 2^21281238584 is an apocalyptic number.

It is an amenable number.

21281238584 is a deficient number, since it is larger than the sum of its proper divisors (18621083776).

21281238584 is a wasteful number, since it uses less digits than its factorization.

21281238584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660154829 (or 2660154825 counting only the distinct ones).

The product of its digits is 245760, while the sum is 44.

The spelling of 21281238584 in words is "twenty-one billion, two hundred eighty-one million, two hundred thirty-eight thousand, five hundred eighty-four".