1213401553 has 12 divisors (see below), whose sum is σ = 1520086260. Its totient is φ = 960053472.

The previous prime is 1213401551. The next prime is 1213401583. The reversal of 1213401553 is 3551043121.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 592046224 + 621355329 = 24332^2 + 24927^2 .

It is not a de Polignac number, because 1213401553 - 2¹ = 1213401551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1213401551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 951798 + ... + 953071.

It is an arithmetic number, because the mean of its divisors is an integer number (126673855).

Almost surely, 2^1213401553 is an apocalyptic number.

1213401553 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1213401553 is a deficient number, since it is larger than the sum of its proper divisors (306684707).

1213401553 is a wasteful number, since it uses less digits than its factorization.

1213401553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1904896 (or 1904889 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1213401553 is about 34833.9138340784. The cubic root of 1213401553 is about 1066.5998431554.

Adding to 1213401553 its reverse (3551043121), we get a palindrome (4764444674).

The spelling of 1213401553 in words is "one billion, two hundred thirteen million, four hundred one thousand, five hundred fifty-three".