19897642 has 8 divisors (see below), whose sum is σ = 29865600. Its totient is φ = 9942444.

The previous prime is 19897627. The next prime is 19897663. The reversal of 19897642 is 24679891.

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

It is a super-3 number, since 3×19897642³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19897592 and 19897601.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3609 + ... + 7267.

It is an arithmetic number, because the mean of its divisors is an integer number (3733200).

Almost surely, 2^19897642 is an apocalyptic number.

19897642 is a deficient number, since it is larger than the sum of its proper divisors (9967958).

19897642 is a wasteful number, since it uses less digits than its factorization.

19897642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6380.

The product of its digits is 217728, while the sum is 46.

The square root of 19897642 is about 4460.6773028319. The cubic root of 19897642 is about 270.9778988253.

The spelling of 19897642 in words is "nineteen million, eight hundred ninety-seven thousand, six hundred forty-two".