19811401 has 3 divisors (see below), whose sum is σ = 19815853. Its totient is φ = 19806950.

The previous prime is 19811399. The next prime is 19811411. The reversal of 19811401 is 10411891.

The square root of 19811401 is 4451.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 19811401 - 2¹ = 19811399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19811411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2226 + ... + 6676.

Almost surely, 2^19811401 is an apocalyptic number.

19811401 is the 4451-st square number.

19811401 is the 2226-th centered octagonal number.

It is an amenable number.

19811401 is a deficient number, since it is larger than the sum of its proper divisors (4452).

19811401 is an frugal number, since it uses more digits than its factorization.

19811401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8902 (or 4451 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 25.

The cubic root of 19811401 is about 270.5858381427.

Multiplying 19811401 by its sum of digits (25), we get a square (495285025 = 22255²).

The spelling of 19811401 in words is "nineteen million, eight hundred eleven thousand, four hundred one".