20641770 has 64 divisors (see below), whose sum is σ = 55728000. Its totient is φ = 5436288.

The previous prime is 20641769. The next prime is 20641811. The reversal of 20641770 is 7714602.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23601 + ... + 24459.

It is an arithmetic number, because the mean of its divisors is an integer number (870750).

Almost surely, 2^20641770 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20641770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27864000).

20641770 is an abundant number, since it is smaller than the sum of its proper divisors (35086230).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20641770 is a wasteful number, since it uses less digits than its factorization.

20641770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 964 (or 958 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 20641770 is about 4543.3214722271. The cubic root of 20641770 is about 274.3146349248.

The spelling of 20641770 in words is "twenty million, six hundred forty-one thousand, seven hundred seventy".