20750645 has 4 divisors (see below), whose sum is σ = 24900780. Its totient is φ = 16600512.

The previous prime is 20750627. The next prime is 20750647. The reversal of 20750645 is 54605702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54605702 = 2 ⋅27302851.

It can be written as a sum of positive squares in 2 ways, for example, as 14485636 + 6265009 = 3806^2 + 2503^2 .

It is a cyclic number.

It is not a de Polignac number, because 20750645 - 2¹² = 20746549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20750647) 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, 2075060 + ... + 2075069.

It is an arithmetic number, because the mean of its divisors is an integer number (6225195).

Almost surely, 2^20750645 is an apocalyptic number.

It is an amenable number.

20750645 is a deficient number, since it is larger than the sum of its proper divisors (4150135).

20750645 is an equidigital number, since it uses as much as digits as its factorization.

20750645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4150134.

The product of its (nonzero) digits is 8400, while the sum is 29.

The square root of 20750645 is about 4555.2875869697. The cubic root of 20750645 is about 274.7960802304.

The spelling of 20750645 in words is "twenty million, seven hundred fifty thousand, six hundred forty-five".