1261645 has 32 divisors (see below), whose sum is σ = 1969920. Its totient is φ = 752640.

The previous prime is 1261643. The next prime is 1261649. The reversal of 1261645 is 5461621.

It is not a de Polignac number, because 1261645 - 2¹ = 1261643 is a prime.

It is a super-3 number, since 3×1261645³ = 6024663117677733375, which contains 333 as substring.

1261645 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11109 + ... + 11221.

It is an arithmetic number, because the mean of its divisors is an integer number (61560).

2^1261645 is an apocalyptic number.

It is an amenable number.

1261645 is a deficient number, since it is larger than the sum of its proper divisors (708275).

1261645 is a wasteful number, since it uses less digits than its factorization.

1261645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165.

The product of its digits is 1440, while the sum is 25.

The square root of 1261645 is about 1123.2297182678. The cubic root of 1261645 is about 108.0552129666.

It can be divided in two parts, 126 and 1645, that added together give a palindrome (1771).

The spelling of 1261645 in words is "one million, two hundred sixty-one thousand, six hundred forty-five".