21065350373 has 4 divisors (see below), whose sum is σ = 21462809868. Its totient is φ = 20667890880.

The previous prime is 21065350343. The next prime is 21065350391. The reversal of 21065350373 is 37305356012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12881796004 + 8183554369 = 113498^2 + 90463^2 .

It is a cyclic number.

It is not a de Polignac number, because 21065350373 - 2⁶ = 21065350309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21065350303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198729668 + ... + 198729773.

It is an arithmetic number, because the mean of its divisors is an integer number (5365702467).

Almost surely, 2^21065350373 is an apocalyptic number.

It is an amenable number.

21065350373 is a deficient number, since it is larger than the sum of its proper divisors (397459495).

21065350373 is an equidigital number, since it uses as much as digits as its factorization.

21065350373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397459494.

The product of its (nonzero) digits is 56700, while the sum is 35.

The spelling of 21065350373 in words is "twenty-one billion, sixty-five million, three hundred fifty thousand, three hundred seventy-three".