1216151223451 has 16 divisors (see below), whose sum is σ = 1281965506560. Its totient is φ = 1150518651840.

The previous prime is 1216151223449. The next prime is 1216151223467. The reversal of 1216151223451 is 1543221516121.

It is a cyclic number.

It is not a de Polignac number, because 1216151223451 - 2¹ = 1216151223449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216151223431) 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, 45567831 + ... + 45594511.

It is an arithmetic number, because the mean of its divisors is an integer number (80122844160).

Almost surely, 2^{1216151223451} is an apocalyptic number.

1216151223451 is a deficient number, since it is larger than the sum of its proper divisors (65814283109).

1216151223451 is a wasteful number, since it uses less digits than its factorization.

1216151223451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29994.

The product of its digits is 14400, while the sum is 34.

Adding to 1216151223451 its reverse (1543221516121), we get a palindrome (2759372739572).

The spelling of 1216151223451 in words is "one trillion, two hundred sixteen billion, one hundred fifty-one million, two hundred twenty-three thousand, four hundred fifty-one".