19009661 has 16 divisors (see below), whose sum is σ = 21800448. Its totient is φ = 16407600.

The previous prime is 19009649. The next prime is 19009663. The reversal of 19009661 is 16690091.

It is a happy number.

It is not a de Polignac number, because 19009661 - 2¹⁴ = 18993277 is a prime.

It is a super-2 number, since 2×19009661² = 722734422669842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19009663) 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, 57266 + ... + 57596.

It is an arithmetic number, because the mean of its divisors is an integer number (1362528).

Almost surely, 2^19009661 is an apocalyptic number.

19009661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19009661 is a deficient number, since it is larger than the sum of its proper divisors (2790787).

19009661 is a wasteful number, since it uses less digits than its factorization.

19009661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 19009661 is about 4360.0069954072. The cubic root of 19009661 is about 266.8853842760.

The spelling of 19009661 in words is "nineteen million, nine thousand, six hundred sixty-one".