19979956 has 24 divisors (see below), whose sum is σ = 37061640. Its totient is φ = 9408000.

The previous prime is 19979941. The next prime is 19979959. The reversal of 19979956 is 65997991.

It can be written as a sum of positive squares in 4 ways, for example, as 443556 + 19536400 = 666^2 + 4420^2 .

It is a junction number, because it is equal to n+sod(n) for n = 19979897 and 19979906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19979959) 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, 2656 + ... + 6856.

It is an arithmetic number, because the mean of its divisors is an integer number (1544235).

Almost surely, 2^19979956 is an apocalyptic number.

It is an amenable number.

19979956 is a deficient number, since it is larger than the sum of its proper divisors (17081684).

19979956 is a wasteful number, since it uses less digits than its factorization.

19979956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4275 (or 4273 counting only the distinct ones).

The product of its digits is 1377810, while the sum is 55.

The square root of 19979956 is about 4469.8944059116. The cubic root of 19979956 is about 271.3510517051.

The spelling of 19979956 in words is "nineteen million, nine hundred seventy-nine thousand, nine hundred fifty-six".