21235803572 has 12 divisors (see below), whose sum is σ = 39348694980. Its totient is φ = 9993319296.

The previous prime is 21235803559. The next prime is 21235803583. The reversal of 21235803572 is 27530853212.

It can be written as a sum of positive squares in 2 ways, for example, as 15132444196 + 6103359376 = 123014^2 + 78124^2 .

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, 156145547 + ... + 156145682.

It is an arithmetic number, because the mean of its divisors is an integer number (3279057915).

Almost surely, 2^21235803572 is an apocalyptic number.

It is an amenable number.

21235803572 is a deficient number, since it is larger than the sum of its proper divisors (18112891408).

21235803572 is a wasteful number, since it uses less digits than its factorization.

21235803572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312291250 (or 312291248 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The spelling of 21235803572 in words is "twenty-one billion, two hundred thirty-five million, eight hundred three thousand, five hundred seventy-two".