19962021 has 4 divisors (see below), whose sum is σ = 26616032. Its totient is φ = 13308012.

The previous prime is 19962017. The next prime is 19962031. The reversal of 19962021 is 12026991.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12026991 = 3 ⋅4008997.

It is not a de Polignac number, because 19962021 - 2² = 19962017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 19962021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19962031) 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, 3327001 + ... + 3327006.

It is an arithmetic number, because the mean of its divisors is an integer number (6654008).

Almost surely, 2^19962021 is an apocalyptic number.

It is an amenable number.

19962021 is a deficient number, since it is larger than the sum of its proper divisors (6654011).

19962021 is an equidigital number, since it uses as much as digits as its factorization.

19962021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6654010.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 19962021 is about 4467.8877559760. The cubic root of 19962021 is about 271.2698346755.

The spelling of 19962021 in words is "nineteen million, nine hundred sixty-two thousand, twenty-one".