1161555461 has 32 divisors (see below), whose sum is σ = 1349332992. Its totient is φ = 990000000.

The previous prime is 1161555427. The next prime is 1161555463. The reversal of 1161555461 is 1645551611.

It is a happy number.

It is not a de Polignac number, because 1161555461 - 2⁶ = 1161555397 is a prime.

It is a super-2 number, since 2×1161555461² = 2698422177957845042, 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 (1161555463) 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, 3509066 + ... + 3509396.

It is an arithmetic number, because the mean of its divisors is an integer number (42166656).

Almost surely, 2^1161555461 is an apocalyptic number.

1161555461 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1161555461 is a deficient number, since it is larger than the sum of its proper divisors (187777531).

1161555461 is a wasteful number, since it uses less digits than its factorization.

1161555461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665.

The product of its digits is 18000, while the sum is 35.

The square root of 1161555461 is about 34081.6000357964. The cubic root of 1161555461 is about 1051.1870056034.

It can be divided in two parts, 11615 and 55461, that added together give a palindrome (67076).

The spelling of 1161555461 in words is "one billion, one hundred sixty-one million, five hundred fifty-five thousand, four hundred sixty-one".