19615961 has 4 divisors (see below), whose sum is σ = 20648400. Its totient is φ = 18583524.

The previous prime is 19615949. The next prime is 19615979. The reversal of 19615961 is 16951691.

It is a happy number.

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 19615961 - 2¹⁰ = 19614937 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19615991) 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, 516191 + ... + 516228.

It is an arithmetic number, because the mean of its divisors is an integer number (5162100).

Almost surely, 2^19615961 is an apocalyptic number.

It is an amenable number.

19615961 is a deficient number, since it is larger than the sum of its proper divisors (1032439).

19615961 is a wasteful number, since it uses less digits than its factorization.

19615961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032438.

The product of its digits is 14580, while the sum is 38.

The square root of 19615961 is about 4428.9909686067. The cubic root of 19615961 is about 269.6931172635.

The spelling of 19615961 in words is "nineteen million, six hundred fifteen thousand, nine hundred sixty-one".