1288821 has 16 divisors (see below), whose sum is σ = 1871424. Its totient is φ = 785664.

The previous prime is 1288817. The next prime is 1288823.

1288821 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1288821 - 2² = 1288817 is a prime.

It is a super-2 number, since 2×1288821² = 3322119140082, which contains 22 as substring.

1288821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1546 + ... + 2228.

It is an arithmetic number, because the mean of its divisors is an integer number (116964).

2^1288821 is an apocalyptic number.

It is an amenable number.

1288821 is a deficient number, since it is larger than the sum of its proper divisors (582603).

1288821 is a wasteful number, since it uses less digits than its factorization.

1288821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740.

The product of its digits is 2048, while the sum is 30.

The square root of 1288821 is about 1135.2625247052. The cubic root of 1288821 is about 108.8255493001.

The spelling of 1288821 in words is "one million, two hundred eighty-eight thousand, eight hundred twenty-one".