1000100025 has 36 divisors (see below), whose sum is σ = 1801714668. Its totient is φ = 530282880.

The previous prime is 1000100009. The next prime is 1000100033. The reversal of 1000100025 is 5200010001.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 99920016 + 900180009 = 9996^2 + 30003^2 .

It is not a de Polignac number, because 1000100025 - 2⁴ = 1000100009 is a prime.

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 26079 + ... + 51771.

Almost surely, 2^1000100025 is an apocalyptic number.

1000100025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1000100025 is a deficient number, since it is larger than the sum of its proper divisors (801614643).

1000100025 is a wasteful number, since it uses less digits than its factorization.

1000100025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25882 (or 25874 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 9.

The square root of 1000100025 is about 31624.3580962523. The cubic root of 1000100025 is about 1000.0333405551.

Adding to 1000100025 its reverse (5200010001), we get a palindrome (6200110026).

It can be divided in two parts, 1000 and 100025, that added together give a triangular number (101025 = T₄₄₉).

The spelling of 1000100025 in words is "one billion, one hundred thousand, twenty-five".