21383521370 has 16 divisors (see below), whose sum is σ = 39530618568. Its totient is φ = 8322235200.

The previous prime is 21383521331. The next prime is 21383521381. The reversal of 21383521370 is 7312538312.

It can be written as a sum of positive squares in 4 ways, for example, as 14082331561 + 7301189809 = 118669^2 + 85447^2 .

It is a super-3 number, since 3×21383521370³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21383521370.

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, 28896281 + ... + 28897020.

Almost surely, 2^21383521370 is an apocalyptic number.

21383521370 is a deficient number, since it is larger than the sum of its proper divisors (18147097198).

21383521370 is a wasteful number, since it uses less digits than its factorization.

21383521370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57793345.

The product of its (nonzero) digits is 30240, while the sum is 35.

The spelling of 21383521370 in words is "twenty-one billion, three hundred eighty-three million, five hundred twenty-one thousand, three hundred seventy".