19970989 has 4 divisors (see below), whose sum is σ = 19991356. Its totient is φ = 19950624.

The previous prime is 19970987. The next prime is 19970999. The reversal of 19970989 is 98907991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19053225 + 917764 = 4365^2 + 958^2 .

It is a cyclic number.

It is not a de Polignac number, because 19970989 - 2¹ = 19970987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19970987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8634 + ... + 10699.

It is an arithmetic number, because the mean of its divisors is an integer number (4997839).

Almost surely, 2^19970989 is an apocalyptic number.

It is an amenable number.

19970989 is a deficient number, since it is larger than the sum of its proper divisors (20367).

19970989 is a wasteful number, since it uses less digits than its factorization.

19970989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20366.

The product of its (nonzero) digits is 367416, while the sum is 52.

The square root of 19970989 is about 4468.8912495159. The cubic root of 19970989 is about 271.3104515326.

The spelling of 19970989 in words is "nineteen million, nine hundred seventy thousand, nine hundred eighty-nine".