1213857553 has 4 divisors (see below), whose sum is σ = 1255714740. Its totient is φ = 1172000368.

The previous prime is 1213857539. The next prime is 1213857583. The reversal of 1213857553 is 3557583121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 762422544 + 451435009 = 27612^2 + 21247^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213857553 - 2²¹ = 1211760401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213857583) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20928550 + ... + 20928607.

It is an arithmetic number, because the mean of its divisors is an integer number (313928685).

Almost surely, 2^1213857553 is an apocalyptic number.

It is an amenable number.

1213857553 is a deficient number, since it is larger than the sum of its proper divisors (41857187).

1213857553 is an equidigital number, since it uses as much as digits as its factorization.

1213857553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41857186.

The product of its digits is 126000, while the sum is 40.

The square root of 1213857553 is about 34840.4585647204. The cubic root of 1213857553 is about 1066.7334369119.

The spelling of 1213857553 in words is "one billion, two hundred thirteen million, eight hundred fifty-seven thousand, five hundred fifty-three".