19859961 has 16 divisors (see below), whose sum is σ = 30587328. Its totient is φ = 11328000.

The previous prime is 19859941. The next prime is 19859963. The reversal of 19859961 is 16995891.

It is not a de Polignac number, because 19859961 - 2⁹ = 19859449 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19859961.

It is not an unprimeable number, because it can be changed into a prime (19859963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17140 + ... + 18261.

It is an arithmetic number, because the mean of its divisors is an integer number (1911708).

Almost surely, 2^19859961 is an apocalyptic number.

19859961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19859961 is a deficient number, since it is larger than the sum of its proper divisors (10727367).

19859961 is a wasteful number, since it uses less digits than its factorization.

19859961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35432.

The product of its digits is 174960, while the sum is 48.

The square root of 19859961 is about 4456.4516153550. The cubic root of 19859961 is about 270.8067366597.

The spelling of 19859961 in words is "nineteen million, eight hundred fifty-nine thousand, nine hundred sixty-one".