1261139 has 4 divisors (see below), whose sum is σ = 1375800. Its totient is φ = 1146480.

The previous prime is 1261133. The next prime is 1261157. The reversal of 1261139 is 9311621.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1261139 - 2¹² = 1257043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57314 + ... + 57335.

It is an arithmetic number, because the mean of its divisors is an integer number (343950).

2^1261139 is an apocalyptic number.

1261139 is a deficient number, since it is larger than the sum of its proper divisors (114661).

1261139 is a wasteful number, since it uses less digits than its factorization.

1261139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114660.

The product of its digits is 324, while the sum is 23.

The square root of 1261139 is about 1123.0044523509. The cubic root of 1261139 is about 108.0407653608.

The spelling of 1261139 in words is "one million, two hundred sixty-one thousand, one hundred thirty-nine".