20545961 has 4 divisors (see below), whose sum is σ = 21047124. Its totient is φ = 20044800.

The previous prime is 20545957. The next prime is 20546023. The reversal of 20545961 is 16954502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10686361 + 9859600 = 3269^2 + 3140^2 .

It is a cyclic number.

It is not a de Polignac number, because 20545961 - 2² = 20545957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20542961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 250520 + ... + 250601.

It is an arithmetic number, because the mean of its divisors is an integer number (5261781).

Almost surely, 2^20545961 is an apocalyptic number.

It is an amenable number.

20545961 is a deficient number, since it is larger than the sum of its proper divisors (501163).

20545961 is an equidigital number, since it uses as much as digits as its factorization.

20545961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 501162.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 20545961 is about 4532.7652707812. The cubic root of 20545961 is about 273.8895651356.

The spelling of 20545961 in words is "twenty million, five hundred forty-five thousand, nine hundred sixty-one".