17745072021 has 24 divisors (see below), whose sum is σ = 26986209120. Its totient is φ = 11205171936.

The previous prime is 17745072019. The next prime is 17745072029. The reversal of 17745072021 is 12027054771.

It is not a de Polignac number, because 17745072021 - 2¹ = 17745072019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17745072029) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1427991 + ... + 1440363.

It is an arithmetic number, because the mean of its divisors is an integer number (1124425380).

Almost surely, 2^17745072021 is an apocalyptic number.

It is an amenable number.

17745072021 is a deficient number, since it is larger than the sum of its proper divisors (9241137099).

17745072021 is a wasteful number, since it uses less digits than its factorization.

17745072021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20785 (or 20782 counting only the distinct ones).

The product of its (nonzero) digits is 27440, while the sum is 36.

The spelling of 17745072021 in words is "seventeen billion, seven hundred forty-five million, seventy-two thousand, twenty-one".