1020111900 has 144 divisors (see below), whose sum is σ = 3126466560. Its totient is φ = 256089600.

The previous prime is 1020111889. The next prime is 1020111913. The reversal of 1020111900 is 91110201.

It is a super-2 number, since 2×1020111900² = 2081256577043220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1020111900.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1088232 + ... + 1089168.

Almost surely, 2^1020111900 is an apocalyptic number.

1020111900 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 1020111900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1563233280).

1020111900 is an abundant number, since it is smaller than the sum of its proper divisors (2106354660).

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

1020111900 is a wasteful number, since it uses less digits than its factorization.

1020111900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1164 (or 1157 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 15.

The square root of 1020111900 is about 31939.1906597522. The cubic root of 1020111900 is about 1006.6595190249.

The spelling of 1020111900 in words is "one billion, twenty million, one hundred eleven thousand, nine hundred".