1000020138 has 64 divisors (see below), whose sum is σ = 2312053632. Its totient is φ = 285603840.

The previous prime is 1000020107. The next prime is 1000020139. The reversal of 1000020138 is 8310200001.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1000020139) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 91633 + ... + 101963.

It is an arithmetic number, because the mean of its divisors is an integer number (36125838).

Almost surely, 2^1000020138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1000020138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1156026816).

1000020138 is an abundant number, since it is smaller than the sum of its proper divisors (1312033494).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1000020138 is a wasteful number, since it uses less digits than its factorization.

1000020138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10439.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1000020138 is about 31623.0950098184. The cubic root of 1000020138 is about 1000.0067126216.

Adding to 1000020138 its reverse (8310200001), we get a palindrome (9310220139).

The spelling of 1000020138 in words is "one billion, twenty thousand, one hundred thirty-eight".