21000011570 has 16 divisors (see below), whose sum is σ = 39103470360. Its totient is φ = 8110349184.

The previous prime is 21000011533. The next prime is 21000011587. The reversal of 21000011570 is 7511000012.

It can be written as a sum of positive squares in 4 ways, for example, as 15967102321 + 5032909249 = 126361^2 + 70943^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36206627 + ... + 36207206.

Almost surely, 2^21000011570 is an apocalyptic number.

21000011570 is a deficient number, since it is larger than the sum of its proper divisors (18103458790).

21000011570 is a wasteful number, since it uses less digits than its factorization.

21000011570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72413869.

The product of its (nonzero) digits is 70, while the sum is 17.

Adding to 21000011570 its reverse (7511000012), we get a palindrome (28511011582).

The spelling of 21000011570 in words is "twenty-one billion, eleven thousand, five hundred seventy".