19426621 has 4 divisors (see below), whose sum is σ = 19598652. Its totient is φ = 19254592.

The previous prime is 19426619. The next prime is 19426633. The reversal of 19426621 is 12662491.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3024121 + 16402500 = 1739^2 + 4050^2 .

It is a cyclic number.

It is not a de Polignac number, because 19426621 - 2¹ = 19426619 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19426601) 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 3 ways as a sum of consecutive naturals, for example, 85846 + ... + 86071.

It is an arithmetic number, because the mean of its divisors is an integer number (4899663).

Almost surely, 2^19426621 is an apocalyptic number.

It is an amenable number.

19426621 is a deficient number, since it is larger than the sum of its proper divisors (172031).

19426621 is a wasteful number, since it uses less digits than its factorization.

19426621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172030.

The product of its digits is 5184, while the sum is 31.

The square root of 19426621 is about 4407.5640664657. The cubic root of 19426621 is about 268.8225867751.

The spelling of 19426621 in words is "nineteen million, four hundred twenty-six thousand, six hundred twenty-one".