20779491 has 16 divisors (see below), whose sum is σ = 29490048. Its totient is φ = 12969600.

The previous prime is 20779489. The next prime is 20779531. The reversal of 20779491 is 19497702.

It is not a de Polignac number, because 20779491 - 2¹ = 20779489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20779411) 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 15 ways as a sum of consecutive naturals, for example, 9796 + ... + 11726.

It is an arithmetic number, because the mean of its divisors is an integer number (1843128).

Almost surely, 2^20779491 is an apocalyptic number.

20779491 is a deficient number, since it is larger than the sum of its proper divisors (8710557).

20779491 is a wasteful number, since it uses less digits than its factorization.

20779491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2162.

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 20779491 is about 4558.4526980106. The cubic root of 20779491 is about 274.9233549488.

The spelling of 20779491 in words is "twenty million, seven hundred seventy-nine thousand, four hundred ninety-one".