19972111 has 2 divisors, whose sum is σ = 19972112. Its totient is φ = 19972110.

The previous prime is 19972079. The next prime is 19972151. The reversal of 19972111 is 11127991.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19972111 - 2⁵ = 19972079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19972151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9986055 + 9986056.

It is an arithmetic number, because the mean of its divisors is an integer number (9986056).

Almost surely, 2^19972111 is an apocalyptic number.

19972111 is a deficient number, since it is larger than the sum of its proper divisors (1).

19972111 is an equidigital number, since it uses as much as digits as its factorization.

19972111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1134, while the sum is 31.

The square root of 19972111 is about 4469.0167822464. The cubic root of 19972111 is about 271.3155323129.

The spelling of 19972111 in words is "nineteen million, nine hundred seventy-two thousand, one hundred eleven".