19959999 has 8 divisors (see below), whose sum is σ = 26637312. Its totient is φ = 13294680.

The previous prime is 19959977. The next prime is 19960009. The reversal of 19959999 is 99995991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19959999 - 2⁹ = 19959487 is a prime.

19959999 is a modest number, since divided by 9999 gives 1995 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19959949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2152 + ... + 6674.

It is an arithmetic number, because the mean of its divisors is an integer number (3329664).

Almost surely, 2^19959999 is an apocalyptic number.

19959999 is a deficient number, since it is larger than the sum of its proper divisors (6677313).

19959999 is a wasteful number, since it uses less digits than its factorization.

19959999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5997.

The product of its digits is 2657205, while the sum is 60.

The square root of 19959999 is about 4467.6614688224. The cubic root of 19959999 is about 271.2606751800.

The spelling of 19959999 in words is "nineteen million, nine hundred fifty-nine thousand, nine hundred ninety-nine".