19690561 has 4 divisors (see below), whose sum is σ = 21480624. Its totient is φ = 17900500.

The previous prime is 19690543. The next prime is 19690577. The reversal of 19690561 is 16509691.

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 19690561 - 2⁹ = 19690049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19690561.

It is not an unprimeable number, because it can be changed into a prime (19690511) 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, 895015 + ... + 895036.

It is an arithmetic number, because the mean of its divisors is an integer number (5370156).

Almost surely, 2^19690561 is an apocalyptic number.

19690561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19690561 is a deficient number, since it is larger than the sum of its proper divisors (1790063).

19690561 is a wasteful number, since it uses less digits than its factorization.

19690561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1790062.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 19690561 is about 4437.4047595413. The cubic root of 19690561 is about 270.0345680478.

The spelling of 19690561 in words is "nineteen million, six hundred ninety thousand, five hundred sixty-one".