1287922 has 4 divisors (see below), whose sum is σ = 1931886. Its totient is φ = 643960.

The previous prime is 1287917. The next prime is 1287947. The reversal of 1287922 is 2297821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2297821 = 73 ⋅31477.

It can be written as a sum of positive squares in only one way, i.e., 1142761 + 145161 = 1069^2 + 381^2 .

It is a super-4 number, since 4×1287922⁴ (a number of 26 digits) contains 4444 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321979 + ... + 321982.

2^1287922 is an apocalyptic number.

1287922 is a deficient number, since it is larger than the sum of its proper divisors (643964).

1287922 is an equidigital number, since it uses as much as digits as its factorization.

1287922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643963.

The product of its digits is 4032, while the sum is 31.

The square root of 1287922 is about 1134.8665119740. The cubic root of 1287922 is about 108.8002401415.

It can be divided in two parts, 1287 and 922, that added together give a square (2209 = 47²).

The spelling of 1287922 in words is "one million, two hundred eighty-seven thousand, nine hundred twenty-two".