1211268720 has 80 divisors (see below), whose sum is σ = 3842289792. Its totient is φ = 315490560.

The previous prime is 1211268689. The next prime is 1211268727. The reversal of 1211268720 is 278621121.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211268727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48366 + ... + 69005.

Almost surely, 2^1211268720 is an apocalyptic number.

1211268720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211268720 is an abundant number, since it is smaller than the sum of its proper divisors (2631021072).

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

1211268720 is a wasteful number, since it uses less digits than its factorization.

1211268720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117430 (or 117424 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 1211268720 is about 34803.2860517509. The cubic root of 1211268720 is about 1065.9745449278.

Adding to 1211268720 its reverse (278621121), we get a palindrome (1489889841).

The spelling of 1211268720 in words is "one billion, two hundred eleven million, two hundred sixty-eight thousand, seven hundred twenty".