1187381 has 8 divisors (see below), whose sum is σ = 1289400. Its totient is φ = 1086912.

The previous prime is 1187369. The next prime is 1187383. The reversal of 1187381 is 1837811.

It can be written as a sum of positive squares in 4 ways, for example, as 167281 + 1020100 = 409^2 + 1010^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1187381 - 2⁶ = 1187317 is a prime.

It is a super-2 number, since 2×1187381² = 2819747278322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1187383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1631 + ... + 2243.

It is an arithmetic number, because the mean of its divisors is an integer number (161175).

2^1187381 is an apocalyptic number.

It is an amenable number.

1187381 is a deficient number, since it is larger than the sum of its proper divisors (102019).

1187381 is a wasteful number, since it uses less digits than its factorization.

1187381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775.

The product of its digits is 1344, while the sum is 29.

The square root of 1187381 is about 1089.6701335725. The cubic root of 1187381 is about 105.8920522040.

It can be divided in two parts, 11 and 87381, that multiplied together give a triangular number (961191 = T₁₃₈₆).

The spelling of 1187381 in words is "one million, one hundred eighty-seven thousand, three hundred eighty-one".