1200001023 has 12 divisors (see below), whose sum is σ = 1866668440. Its totient is φ = 738462096.

The previous prime is 1200001013. The next prime is 1200001051. The reversal of 1200001023 is 3201000021.

It is a happy number.

It is not a de Polignac number, because 1200001023 - 2¹³ = 1199992831 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1200000996 and 1200001014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200001013) 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, 5128093 + ... + 5128326.

Almost surely, 2^1200001023 is an apocalyptic number.

1200001023 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1200001023 is a deficient number, since it is larger than the sum of its proper divisors (666667417).

1200001023 is a wasteful number, since it uses less digits than its factorization.

1200001023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10256438 (or 10256435 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 1200001023 is about 34641.0309171075. The cubic root of 1200001023 is about 1062.6588711547.

Adding to 1200001023 its reverse (3201000021), we get a palindrome (4401001044).

The spelling of 1200001023 in words is "one billion, two hundred million, one thousand, twenty-three".