19559421 has 32 divisors (see below), whose sum is σ = 34023680. Its totient is φ = 10870848.

The previous prime is 19559413. The next prime is 19559429. The reversal of 19559421 is 12495591.

It is an interprime number because it is at equal distance from previous prime (19559413) and next prime (19559429).

It is not a de Polignac number, because 19559421 - 2³ = 19559413 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 (19559429) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5595 + ... + 8391.

It is an arithmetic number, because the mean of its divisors is an integer number (1063240).

Almost surely, 2^19559421 is an apocalyptic number.

It is an amenable number.

19559421 is a deficient number, since it is larger than the sum of its proper divisors (14464259).

19559421 is a wasteful number, since it uses less digits than its factorization.

19559421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2850 (or 2844 counting only the distinct ones).

The product of its digits is 16200, while the sum is 36.

The square root of 19559421 is about 4422.6034188021. The cubic root of 19559421 is about 269.4337515562.

Subtracting from 19559421 its sum of digits (36), we obtain a triangular number (19559385 = T₆₂₅₄).

The spelling of 19559421 in words is "nineteen million, five hundred fifty-nine thousand, four hundred twenty-one".