21788745652 has 12 divisors (see below), whose sum is σ = 38132532900. Its totient is φ = 10893736256.

The previous prime is 21788745637. The next prime is 21788745749. The reversal of 21788745652 is 25654788712.

It can be written as a sum of positive squares in 2 ways, for example, as 4944339856 + 16844405796 = 70316^2 + 129786^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21788745593 and 21788745602.

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, 77473 + ... + 222664.

It is an arithmetic number, because the mean of its divisors is an integer number (3177711075).

Almost surely, 2^21788745652 is an apocalyptic number.

It is an amenable number.

21788745652 is a deficient number, since it is larger than the sum of its proper divisors (16343787248).

21788745652 is a wasteful number, since it uses less digits than its factorization.

21788745652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318290 (or 318288 counting only the distinct ones).

The product of its digits is 7526400, while the sum is 55.

The spelling of 21788745652 in words is "twenty-one billion, seven hundred eighty-eight million, seven hundred forty-five thousand, six hundred fifty-two".