20631779 has 8 divisors (see below), whose sum is σ = 23931648. Its totient is φ = 17420040.

The previous prime is 20631773. The next prime is 20631781. The reversal of 20631779 is 97713602.

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

It is a cyclic number.

It is not a de Polignac number, because 20631779 - 2⁴ = 20631763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20631773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21527 + ... + 22464.

It is an arithmetic number, because the mean of its divisors is an integer number (2991456).

Almost surely, 2^20631779 is an apocalyptic number.

20631779 is a deficient number, since it is larger than the sum of its proper divisors (3299869).

20631779 is an equidigital number, since it uses as much as digits as its factorization.

20631779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44065.

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 20631779 is about 4542.2218131659. The cubic root of 20631779 is about 274.2703699899.

The spelling of 20631779 in words is "twenty million, six hundred thirty-one thousand, seven hundred seventy-nine".