1157661 has 6 divisors (see below), whose sum is σ = 1672190. Its totient is φ = 771768.

The previous prime is 1157641. The next prime is 1157669. The reversal of 1157661 is 1667511.

It can be written as a sum of positive squares in only one way, i.e., 1071225 + 86436 = 1035^2 + 294^2 .

It is not a de Polignac number, because 1157661 - 2¹⁰ = 1156637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1157669) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 64306 + ... + 64323.

2^1157661 is an apocalyptic number.

It is an amenable number.

1157661 is a deficient number, since it is larger than the sum of its proper divisors (514529).

1157661 is a wasteful number, since it uses less digits than its factorization.

1157661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128635 (or 128632 counting only the distinct ones).

The product of its digits is 1260, while the sum is 27.

The square root of 1157661 is about 1075.9465600112. The cubic root of 1157661 is about 105.0010884241.

It can be divided in two parts, 115 and 7661, that added together give a 5-th power (7776 = 6⁵).

The spelling of 1157661 in words is "one million, one hundred fifty-seven thousand, six hundred sixty-one".