21143578952 has 8 divisors (see below), whose sum is σ = 39644210550. Its totient is φ = 10571789472.

The previous prime is 21143578913. The next prime is 21143578969. The reversal of 21143578952 is 25987534112.

It can be written as a sum of positive squares in only one way, i.e., 10854722596 + 10288856356 = 104186^2 + 101434^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21143578897 and 21143578906.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321473677 + ... + 1321473692.

Almost surely, 2^21143578952 is an apocalyptic number.

It is an amenable number.

21143578952 is a deficient number, since it is larger than the sum of its proper divisors (18500631598).

21143578952 is a wasteful number, since it uses less digits than its factorization.

21143578952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2642947375 (or 2642947371 counting only the distinct ones).

The product of its digits is 604800, while the sum is 47.

The spelling of 21143578952 in words is "twenty-one billion, one hundred forty-three million, five hundred seventy-eight thousand, nine hundred fifty-two".