21017533370 has 16 divisors (see below), whose sum is σ = 39136097160. Its totient is φ = 8117116224.

The previous prime is 21017533343. The next prime is 21017533409. The reversal of 21017533370 is 7333571012.

It can be written as a sum of positive squares in 4 ways, for example, as 19016134201 + 2001399169 = 137899^2 + 44737^2 .

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, 36236837 + ... + 36237416.

Almost surely, 2^21017533370 is an apocalyptic number.

21017533370 is a deficient number, since it is larger than the sum of its proper divisors (18118563790).

21017533370 is a wasteful number, since it uses less digits than its factorization.

21017533370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72474289.

The product of its (nonzero) digits is 13230, while the sum is 32.

The spelling of 21017533370 in words is "twenty-one billion, seventeen million, five hundred thirty-three thousand, three hundred seventy".