1972891 has 2 divisors, whose sum is σ = 1972892. Its totient is φ = 1972890.

The previous prime is 1972889. The next prime is 1972913. The reversal of 1972891 is 1982791.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1972891 - 2¹ = 1972889 is a prime.

Together with 1972889, it forms a pair of twin primes.

1972891 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1972891.

It is not a weakly prime, because it can be changed into another prime (1972291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 986445 + 986446.

It is an arithmetic number, because the mean of its divisors is an integer number (986446).

2^1972891 is an apocalyptic number.

1972891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1972891 is an equidigital number, since it uses as much as digits as its factorization.

1972891 is an evil number, because the sum of its binary digits is even.

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

The square root of 1972891 is about 1404.5963833073. The cubic root of 1972891 is about 125.4202601345.

The spelling of 1972891 in words is "one million, nine hundred seventy-two thousand, eight hundred ninety-one".