19906261 has 4 divisors (see below), whose sum is σ = 19929024. Its totient is φ = 19883500.

The previous prime is 19906241. The next prime is 19906273. The reversal of 19906261 is 16260991.

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 19906261 - 2²¹ = 17809109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19906241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10015 + ... + 11836.

It is an arithmetic number, because the mean of its divisors is an integer number (4982256).

Almost surely, 2^19906261 is an apocalyptic number.

It is an amenable number.

19906261 is a deficient number, since it is larger than the sum of its proper divisors (22763).

19906261 is an equidigital number, since it uses as much as digits as its factorization.

19906261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22762.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 19906261 is about 4461.6433071235. The cubic root of 19906261 is about 271.0170193965.

The spelling of 19906261 in words is "nineteen million, nine hundred six thousand, two hundred sixty-one".