1243155554 has 4 divisors (see below), whose sum is σ = 1864733334. Its totient is φ = 621577776.

The previous prime is 1243155533. The next prime is 1243155569. The reversal of 1243155554 is 4555513421.

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

It can be written as a sum of positive squares in only one way, i.e., 1104033529 + 139122025 = 33227^2 + 11795^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310788887 + ... + 310788890.

Almost surely, 2^1243155554 is an apocalyptic number.

1243155554 is a deficient number, since it is larger than the sum of its proper divisors (621577780).

1243155554 is an equidigital number, since it uses as much as digits as its factorization.

1243155554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621577779.

The product of its digits is 60000, while the sum is 35.

The square root of 1243155554 is about 35258.4111099749. The cubic root of 1243155554 is about 1075.2476239367.

Adding to 1243155554 its reverse (4555513421), we get a palindrome (5798668975).

The spelling of 1243155554 in words is "one billion, two hundred forty-three million, one hundred fifty-five thousand, five hundred fifty-four".