1221116455 has 16 divisors (see below), whose sum is σ = 1580289984. Its totient is φ = 900472320.

The previous prime is 1221116431. The next prime is 1221116461. The reversal of 1221116455 is 5546111221.

It is not a de Polignac number, because 1221116455 - 2¹¹ = 1221114407 is a prime.

It is a super-2 number, since 2×1221116455² = 2982250793343534050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34335 + ... + 60175.

It is an arithmetic number, because the mean of its divisors is an integer number (98768124).

Almost surely, 2^1221116455 is an apocalyptic number.

1221116455 is a deficient number, since it is larger than the sum of its proper divisors (359173529).

1221116455 is a wasteful number, since it uses less digits than its factorization.

1221116455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26586.

The product of its digits is 2400, while the sum is 28.

The square root of 1221116455 is about 34944.4767452598. The cubic root of 1221116455 is about 1068.8555775914.

Adding to 1221116455 its reverse (5546111221), we get a palindrome (6767227676).

The spelling of 1221116455 in words is "one billion, two hundred twenty-one million, one hundred sixteen thousand, four hundred fifty-five".