1211115664 has 20 divisors (see below), whose sum is σ = 2559858480. Its totient is φ = 550507040.

The previous prime is 1211115641. The next prime is 1211115673. The reversal of 1211115664 is 4665111121.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3440494 + ... + 3440845.

It is an arithmetic number, because the mean of its divisors is an integer number (127992924).

Almost surely, 2^1211115664 is an apocalyptic number.

It is an amenable number.

1211115664 is an abundant number, since it is smaller than the sum of its proper divisors (1348742816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211115664 is a wasteful number, since it uses less digits than its factorization.

1211115664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6881358 (or 6881352 counting only the distinct ones).

The product of its digits is 1440, while the sum is 28.

The square root of 1211115664 is about 34801.0871094568. The cubic root of 1211115664 is about 1065.9296441639.

Adding to 1211115664 its reverse (4665111121), we get a palindrome (5876226785).

The spelling of 1211115664 in words is "one billion, two hundred eleven million, one hundred fifteen thousand, six hundred sixty-four".