19621997 has 8 divisors (see below), whose sum is σ = 19881600. Its totient is φ = 19364400.

The previous prime is 19621969. The next prime is 19622021. The reversal of 19621997 is 79912691.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19621997 - 2⁶ = 19621933 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 (19621937) 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 7 ways as a sum of consecutive naturals, for example, 29723 + ... + 30375.

It is an arithmetic number, because the mean of its divisors is an integer number (2485200).

Almost surely, 2^19621997 is an apocalyptic number.

It is an amenable number.

19621997 is a deficient number, since it is larger than the sum of its proper divisors (259603).

19621997 is a wasteful number, since it uses less digits than its factorization.

19621997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1003.

The product of its digits is 61236, while the sum is 44.

The square root of 19621997 is about 4429.6723355120. The cubic root of 19621997 is about 269.7207767243.

The spelling of 19621997 in words is "nineteen million, six hundred twenty-one thousand, nine hundred ninety-seven".