1211665461 has 32 divisors (see below), whose sum is σ = 1716809472. Its totient is φ = 758545920.

The previous prime is 1211665417. The next prime is 1211665487. The reversal of 1211665461 is 1645661121.

It is not a de Polignac number, because 1211665461 - 2²² = 1207471157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211665061) 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, 1475431 + ... + 1476251.

It is an arithmetic number, because the mean of its divisors is an integer number (53650296).

Almost surely, 2^1211665461 is an apocalyptic number.

It is an amenable number.

1211665461 is a deficient number, since it is larger than the sum of its proper divisors (505144011).

1211665461 is a wasteful number, since it uses less digits than its factorization.

1211665461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1213.

The product of its digits is 8640, while the sum is 33.

The square root of 1211665461 is about 34808.9853486137. The cubic root of 1211665461 is about 1066.0909159235.

It can be divided in two parts, 12116 and 65461, that added together give a palindrome (77577).

The spelling of 1211665461 in words is "one billion, two hundred eleven million, six hundred sixty-five thousand, four hundred sixty-one".