19780897 has 12 divisors (see below), whose sum is σ = 21051604. Its totient is φ = 18580320.

The previous prime is 19780861. The next prime is 19780907. The reversal of 19780897 is 79808791.

It can be written as a sum of positive squares in 2 ways, for example, as 279841 + 19501056 = 529^2 + 4416^2 .

It is not a de Polignac number, because 19780897 - 2¹¹ = 19778849 is a prime.

It is a super-2 number, since 2×19780897² = 782567772249218, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19780897.

It is not an unprimeable number, because it can be changed into a prime (19780837) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31963 + ... + 32575.

Almost surely, 2^19780897 is an apocalyptic number.

It is an amenable number.

19780897 is a deficient number, since it is larger than the sum of its proper divisors (1270707).

19780897 is an equidigital number, since it uses as much as digits as its factorization.

19780897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720 (or 697 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 19780897 is about 4447.5720342677. The cubic root of 19780897 is about 270.4468913768.

The spelling of 19780897 in words is "nineteen million, seven hundred eighty thousand, eight hundred ninety-seven".