20674779840 has 672 divisors, whose sum is σ = 88489267776. Its totient is φ = 4352901120.

The previous prime is 20674779817. The next prime is 20674779973. The reversal of 20674779840 is 4897747602.

20674779840 is a `hidden beast` number, since 20 + 67 + 477 + 98 + 4 + 0 = 666.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 6999804 + ... + 7002756.

It is an arithmetic number, because the mean of its divisors is an integer number (131680458).

Almost surely, 2^20674779840 is an apocalyptic number.

20674779840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20674779840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44244633888).

20674779840 is an abundant number, since it is smaller than the sum of its proper divisors (67814487936).

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

20674779840 is a wasteful number, since it uses less digits than its factorization.

20674779840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3017 (or 3004 counting only the distinct ones).

The product of its (nonzero) digits is 4741632, while the sum is 54.

The spelling of 20674779840 in words is "twenty billion, six hundred seventy-four million, seven hundred seventy-nine thousand, eight hundred forty".