1020012100020 has 144 divisors (see below), whose sum is σ = 3146643671808. Its totient is φ = 267415603200.

The previous prime is 1020012100007. The next prime is 1020012100021. The reversal of 1020012100020 is 200012100201.

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 = 1020012099975 and 1020012100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020012100021) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2443017 + ... + 2829903.

Almost surely, 2^{1020012100020} is an apocalyptic number.

1020012100020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1020012100020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1573321835904).

1020012100020 is an abundant number, since it is smaller than the sum of its proper divisors (2126631571788).

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

1020012100020 is a wasteful number, since it uses less digits than its factorization.

1020012100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387150 (or 387145 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1020012100020 its reverse (200012100201), we get a palindrome (1220024200221).

The spelling of 1020012100020 in words is "one trillion, twenty billion, twelve million, one hundred thousand, twenty".