19561995 has 24 divisors (see below), whose sum is σ = 34216416. Its totient is φ = 10338048.

The previous prime is 19561973. The next prime is 19561999. The reversal of 19561995 is 59916591.

It is a happy number.

It is not a de Polignac number, because 19561995 - 2¹² = 19557899 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 19561995.

It is not an unprimeable number, because it can be changed into a prime (19561999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3162 + ... + 7008.

It is an arithmetic number, because the mean of its divisors is an integer number (1425684).

Almost surely, 2^19561995 is an apocalyptic number.

19561995 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19561995 is a deficient number, since it is larger than the sum of its proper divisors (14654421).

19561995 is a wasteful number, since it uses less digits than its factorization.

19561995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3971 (or 3968 counting only the distinct ones).

The product of its digits is 109350, while the sum is 45.

The square root of 19561995 is about 4422.8944142948. The cubic root of 19561995 is about 269.4455701074.

The spelling of 19561995 in words is "nineteen million, five hundred sixty-one thousand, nine hundred ninety-five".