19978201 has 4 divisors (see below), whose sum is σ = 20019712. Its totient is φ = 19936692.

The previous prime is 19978199. The next prime is 19978219. The reversal of 19978201 is 10287991.

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 19978201 - 2¹ = 19978199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19978241) 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, 20025 + ... + 20998.

It is an arithmetic number, because the mean of its divisors is an integer number (5004928).

Almost surely, 2^19978201 is an apocalyptic number.

It is an amenable number.

19978201 is a deficient number, since it is larger than the sum of its proper divisors (41511).

19978201 is an equidigital number, since it uses as much as digits as its factorization.

19978201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41510.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 19978201 is about 4469.6980882382. The cubic root of 19978201 is about 271.3431064917.

It can be divided in two parts, 199 and 78201, that added together give a square (78400 = 280²).

The spelling of 19978201 in words is "nineteen million, nine hundred seventy-eight thousand, two hundred one".