20745645 has 8 divisors (see below), whose sum is σ = 33193056. Its totient is φ = 11064336.

The previous prime is 20745629. The next prime is 20745649. The reversal of 20745645 is 54654702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20745645 - 2⁴ = 20745629 is a prime.

It is a super-3 number, since 3×20745645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20745649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 691507 + ... + 691536.

It is an arithmetic number, because the mean of its divisors is an integer number (4149132).

Almost surely, 2^20745645 is an apocalyptic number.

It is an amenable number.

20745645 is a deficient number, since it is larger than the sum of its proper divisors (12447411).

20745645 is a wasteful number, since it uses less digits than its factorization.

20745645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383051.

The product of its (nonzero) digits is 33600, while the sum is 33.

The square root of 20745645 is about 4554.7387411354. The cubic root of 20745645 is about 274.7740071692.

The spelling of 20745645 in words is "twenty million, seven hundred forty-five thousand, six hundred forty-five".