20975629 has 4 divisors (see below), whose sum is σ = 20985084. Its totient is φ = 20966176.

The previous prime is 20975627. The next prime is 20975657. The reversal of 20975629 is 92657902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 11222500 + 9753129 = 3350^2 + 3123^2 .

It is a cyclic number.

It is not a de Polignac number, because 20975629 - 2¹ = 20975627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20975591 and 20975600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20975627) 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, 609 + ... + 6505.

It is an arithmetic number, because the mean of its divisors is an integer number (5246271).

Almost surely, 2^20975629 is an apocalyptic number.

It is an amenable number.

20975629 is a deficient number, since it is larger than the sum of its proper divisors (9455).

20975629 is an equidigital number, since it uses as much as digits as its factorization.

20975629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9454.

The product of its (nonzero) digits is 68040, while the sum is 40.

The square root of 20975629 is about 4579.9158289209. The cubic root of 20975629 is about 275.7856497521.

The spelling of 20975629 in words is "twenty million, nine hundred seventy-five thousand, six hundred twenty-nine".