1243555042 has 4 divisors (see below), whose sum is σ = 1865332566. Its totient is φ = 621777520.

The previous prime is 1243555031. The next prime is 1243555057. The reversal of 1243555042 is 2405553421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2405553421 = 7547 ⋅318743.

It can be written as a sum of positive squares in only one way, i.e., 732297721 + 511257321 = 27061^2 + 22611^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1243554995 and 1243555013.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310888759 + ... + 310888762.

Almost surely, 2^1243555042 is an apocalyptic number.

1243555042 is a deficient number, since it is larger than the sum of its proper divisors (621777524).

1243555042 is an equidigital number, since it uses as much as digits as its factorization.

1243555042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621777523.

The product of its (nonzero) digits is 24000, while the sum is 31.

The square root of 1243555042 is about 35264.0757996009. The cubic root of 1243555042 is about 1075.3627885321.

The spelling of 1243555042 in words is "one billion, two hundred forty-three million, five hundred fifty-five thousand, forty-two".