21017545373 has 4 divisors (see below), whose sum is σ = 22928231328. Its totient is φ = 19106859420.

The previous prime is 21017545319. The next prime is 21017545387. The reversal of 21017545373 is 37354571012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-21017545373 is a prime.

It is a super-2 number, since 2×21017545373² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21017545313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 955342961 + ... + 955342982.

It is an arithmetic number, because the mean of its divisors is an integer number (5732057832).

Almost surely, 2^21017545373 is an apocalyptic number.

It is an amenable number.

21017545373 is a deficient number, since it is larger than the sum of its proper divisors (1910685955).

21017545373 is a wasteful number, since it uses less digits than its factorization.

21017545373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1910685954.

The product of its (nonzero) digits is 88200, while the sum is 38.

The spelling of 21017545373 in words is "twenty-one billion, seventeen million, five hundred forty-five thousand, three hundred seventy-three".