1213553121 has 32 divisors (see below), whose sum is σ = 1816528896. Its totient is φ = 714168000.

The previous prime is 1213553101. The next prime is 1213553147.

1213553121 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1213553121 - 2⁶ = 1213553057 is a prime.

It is a super-2 number, since 2×1213553121² = 2945422354977681282, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1213553091 and 1213553100.

It is not an unprimeable number, because it can be changed into a prime (1213553101) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1111786 + ... + 1112876.

It is an arithmetic number, because the mean of its divisors is an integer number (56766528).

Almost surely, 2^1213553121 is an apocalyptic number.

1213553121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1213553121 is a deficient number, since it is larger than the sum of its proper divisors (602975775).

1213553121 is a wasteful number, since it uses less digits than its factorization.

1213553121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2053.

The product of its digits is 900, while the sum is 24.

The square root of 1213553121 is about 34836.0893471124. The cubic root of 1213553121 is about 1066.6442515580.

It can be divided in two parts, 12135 and 53121, that added together give a palindrome (65256).

The spelling of 1213553121 in words is "one billion, two hundred thirteen million, five hundred fifty-three thousand, one hundred twenty-one".