1021400100 has 648 divisors, whose sum is σ = 4167858240. Its totient is φ = 207567360.

The previous prime is 1021400063. The next prime is 1021400111. The reversal of 1021400100 is 10041201.

It is a happy number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 19271674 + ... + 19271726.

It is an arithmetic number, because the mean of its divisors is an integer number (6431880).

Almost surely, 2^1021400100 is an apocalyptic number.

1021400100 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 1021400100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2083929120).

1021400100 is an abundant number, since it is smaller than the sum of its proper divisors (3146458140).

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

1021400100 is a wasteful number, since it uses less digits than its factorization.

1021400100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 112 counting only the distinct ones).

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

The square root of 1021400100 is about 31959.3507443440. The cubic root of 1021400100 is about 1007.0830782170.

Adding to 1021400100 its reverse (10041201), we get a palindrome (1031441301).

The spelling of 1021400100 in words is "one billion, twenty-one million, four hundred thousand, one hundred".