1781042002 has 4 divisors (see below), whose sum is σ = 2671563006. Its totient is φ = 890521000.

The previous prime is 1781041987. The next prime is 1781042119. The reversal of 1781042002 is 2002401871.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2002401871 = 12401 ⋅161471.

It can be written as a sum of positive squares in only one way, i.e., 1732307641 + 48734361 = 41621^2 + 6981^2 .

It is a super-2 number, since 2×1781042002² = 6344221225776336008, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445260499 + ... + 445260502.

Almost surely, 2^1781042002 is an apocalyptic number.

1781042002 is a deficient number, since it is larger than the sum of its proper divisors (890521004).

1781042002 is an equidigital number, since it uses as much as digits as its factorization.

1781042002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890521003.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 1781042002 is about 42202.3933207585. The cubic root of 1781042002 is about 1212.1547113587.

Adding to 1781042002 its reverse (2002401871), we get a palindrome (3783443873).

The spelling of 1781042002 in words is "one billion, seven hundred eighty-one million, forty-two thousand, two".