19997136 has 30 divisors (see below), whose sum is σ = 55964610. Its totient is φ = 6665664.

The previous prime is 19997129. The next prime is 19997147. The reversal of 19997136 is 63179991.

It can be written as a sum of positive squares in only one way, i.e., 10112400 + 9884736 = 3180^2 + 3144^2 .

It is a super-4 number, since 4×19997136⁴ (a number of 30 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19997091 and 19997100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 69291 + ... + 69578.

It is an arithmetic number, because the mean of its divisors is an integer number (1865487).

Almost surely, 2^19997136 is an apocalyptic number.

19997136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19997136 is an abundant number, since it is smaller than the sum of its proper divisors (35967474).

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

19997136 is a wasteful number, since it uses less digits than its factorization.

19997136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138883 (or 138874 counting only the distinct ones).

The product of its digits is 91854, while the sum is 45.

The square root of 19997136 is about 4471.8157386010. The cubic root of 19997136 is about 271.4288042209.

The spelling of 19997136 in words is "nineteen million, nine hundred ninety-seven thousand, one hundred thirty-six".