1156639 has 10 divisors (see below), whose sum is σ = 1288400. Its totient is φ = 1038180.

The previous prime is 1156637. The next prime is 1156643. The reversal of 1156639 is 9366511.

It is not a de Polignac number, because 1156639 - 2¹ = 1156637 is a prime.

It is an Ulam number.

It is a Duffinian number.

Its product of digits (4860) is a multiple of the sum of its prime divisors (90).

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 1156639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1156633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 14602 + ... + 14680.

It is an arithmetic number, because the mean of its divisors is an integer number (128840).

2^1156639 is an apocalyptic number.

1156639 is a deficient number, since it is larger than the sum of its proper divisors (131761).

1156639 is an frugal number, since it uses more digits than its factorization.

1156639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 90 counting only the distinct ones).

The product of its digits is 4860, while the sum is 31.

The square root of 1156639 is about 1075.4715244952. The cubic root of 1156639 is about 104.9701804967.

The spelling of 1156639 in words is "one million, one hundred fifty-six thousand, six hundred thirty-nine".