19961597 has 4 divisors (see below), whose sum is σ = 19990080. Its totient is φ = 19933116.

The previous prime is 19961593. The next prime is 19961603. The reversal of 19961597 is 79516991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19961597 - 2² = 19961593 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 (19961593) 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, 13163 + ... + 14600.

It is an arithmetic number, because the mean of its divisors is an integer number (4997520).

Almost surely, 2^19961597 is an apocalyptic number.

It is an amenable number.

19961597 is a deficient number, since it is larger than the sum of its proper divisors (28483).

19961597 is an equidigital number, since it uses as much as digits as its factorization.

19961597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28482.

The product of its digits is 153090, while the sum is 47.

The square root of 19961597 is about 4467.8403060092. The cubic root of 19961597 is about 271.2679140412.

The spelling of 19961597 in words is "nineteen million, nine hundred sixty-one thousand, five hundred ninety-seven".