1261399 has 4 divisors (see below), whose sum is σ = 1271160. Its totient is φ = 1251640.

The previous prime is 1261387. The next prime is 1261411. The reversal of 1261399 is 9931621.

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

It is an interprime number because it is at equal distance from previous prime (1261387) and next prime (1261411).

It is a cyclic number.

It is not a de Polignac number, because 1261399 - 2⁹ = 1260887 is a prime.

It is a super-2 number, since 2×1261399² = 3182254874402, which contains 22 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 a Duffinian number.

1261399 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1261399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261199) 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, 4684 + ... + 4945.

It is an arithmetic number, because the mean of its divisors is an integer number (317790).

2^1261399 is an apocalyptic number.

1261399 is a deficient number, since it is larger than the sum of its proper divisors (9761).

1261399 is an equidigital number, since it uses as much as digits as its factorization.

1261399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9760.

The product of its digits is 2916, while the sum is 31.

The square root of 1261399 is about 1123.1202072797. The cubic root of 1261399 is about 108.0481895143.

The spelling of 1261399 in words is "one million, two hundred sixty-one thousand, three hundred ninety-nine".