1901987 has 2 divisors, whose sum is σ = 1901988. Its totient is φ = 1901986.

The previous prime is 1901981. The next prime is 1901993. The reversal of 1901987 is 7891091.

It is a balanced prime because it is at equal distance from previous prime (1901981) and next prime (1901993).

It is a cyclic number.

It is not a de Polignac number, because 1901987 - 2⁶ = 1901923 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1901981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950993 + 950994.

It is an arithmetic number, because the mean of its divisors is an integer number (950994).

2^1901987 is an apocalyptic number.

1901987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1901987 is an equidigital number, since it uses as much as digits as its factorization.

1901987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 1901987 is about 1379.1254475210. The cubic root of 1901987 is about 123.8993937690.

The spelling of 1901987 in words is "one million, nine hundred one thousand, nine hundred eighty-seven".