1216054401651 has 16 divisors (see below), whose sum is σ = 1810707069600. Its totient is φ = 806587687584.

The previous prime is 1216054401647. The next prime is 1216054401659. The reversal of 1216054401651 is 1561044506121.

1216054401651 is a `hidden beast` number, since 1 + 2 + 1 + 60 + 544 + 0 + 1 + 6 + 51 = 666.

It is not a de Polignac number, because 1216054401651 - 2² = 1216054401647 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1216054401659) 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, 114306996 + ... + 114317633.

It is an arithmetic number, because the mean of its divisors is an integer number (113169191850).

Almost surely, 2^{1216054401651} is an apocalyptic number.

1216054401651 is a deficient number, since it is larger than the sum of its proper divisors (594652667949).

1216054401651 is a wasteful number, since it uses less digits than its factorization.

1216054401651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228624835 (or 228624829 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

Adding to 1216054401651 its reverse (1561044506121), we get a palindrome (2777098907772).

The spelling of 1216054401651 in words is "one trillion, two hundred sixteen billion, fifty-four million, four hundred one thousand, six hundred fifty-one".