1211615338756 has 27 divisors (see below), whose sum is σ = 2216615778741. Its totient is φ = 579443989344.

The previous prime is 1211615338751. The next prime is 1211615338763. The reversal of 1211615338756 is 6578335161121.

The square root of 1211615338756 is 1100734.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 836189540356 + 375425798400 = 914434^2 + 612720^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211615338751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 50621800 + ... + 50645728.

Almost surely, 2^{1211615338756} is an apocalyptic number.

1211615338756 is the 1100734-th square number.

It is an amenable number.

1211615338756 is a deficient number, since it is larger than the sum of its proper divisors (1005000439985).

1211615338756 is an frugal number, since it uses more digits than its factorization.

1211615338756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47908 (or 23954 counting only the distinct ones).

The product of its digits is 907200, while the sum is 49.

Multiplying 1211615338756 by its sum of digits (49), we get a square (59369151599044 = 7705138²).

The spelling of 1211615338756 in words is "one trillion, two hundred eleven billion, six hundred fifteen million, three hundred thirty-eight thousand, seven hundred fifty-six".