1221105451455 has 48 divisors (see below), whose sum is σ = 2155929499776. Its totient is φ = 639195701760.

The previous prime is 1221105451451. The next prime is 1221105451477. The reversal of 1221105451455 is 5541545011221.

1221105451455 is a `hidden beast` number, since 1 + 22 + 110 + 5 + 4 + 514 + 5 + 5 = 666.

It is not a de Polignac number, because 1221105451455 - 2² = 1221105451451 is a prime.

It is a super-3 number, since 3×1221105451455³ (a number of 37 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221105451451) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 790539 + ... + 1751331.

It is an arithmetic number, because the mean of its divisors is an integer number (44915197912).

Almost surely, 2^{1221105451455} is an apocalyptic number.

1221105451455 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1221105451455 is a deficient number, since it is larger than the sum of its proper divisors (934824048321).

1221105451455 is a wasteful number, since it uses less digits than its factorization.

1221105451455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961328 (or 961325 counting only the distinct ones).

The product of its (nonzero) digits is 40000, while the sum is 36.

The spelling of 1221105451455 in words is "one trillion, two hundred twenty-one billion, one hundred five million, four hundred fifty-one thousand, four hundred fifty-five".