19718977956 has 24 divisors (see below), whose sum is σ = 46013281440. Its totient is φ = 6572659392.

The previous prime is 19718977951. The next prime is 19718977997. The reversal of 19718977956 is 65977981791.

It is a super-3 number, since 3×19718977956³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (19718977951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 359080 + ... + 410336.

It is an arithmetic number, because the mean of its divisors is an integer number (1917220060).

Almost surely, 2^19718977956 is an apocalyptic number.

It is an amenable number.

19718977956 is an abundant number, since it is smaller than the sum of its proper divisors (26294303484).

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

19718977956 is a wasteful number, since it uses less digits than its factorization.

19718977956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83323 (or 83321 counting only the distinct ones).

The product of its digits is 60011280, while the sum is 69.

The spelling of 19718977956 in words is "nineteen billion, seven hundred eighteen million, nine hundred seventy-seven thousand, nine hundred fifty-six".