1021210020 has 72 divisors (see below), whose sum is σ = 3101402304. Its totient is φ = 271994688.

The previous prime is 1021210013. The next prime is 1021210037. The reversal of 1021210020 is 200121201.

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 = 1021209984 and 1021210011.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 171127 + ... + 176993.

It is an arithmetic number, because the mean of its divisors is an integer number (43075032).

Almost surely, 2^1021210020 is an apocalyptic number.

1021210020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021210020 is an abundant number, since it is smaller than the sum of its proper divisors (2080192284).

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

1021210020 is a wasteful number, since it uses less digits than its factorization.

1021210020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6849 (or 6844 counting only the distinct ones).

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

The square root of 1021210020 is about 31956.3768284203. The cubic root of 1021210020 is about 1007.0206024619.

Adding to 1021210020 its reverse (200121201), we get a palindrome (1221331221).

The spelling of 1021210020 in words is "one billion, twenty-one million, two hundred ten thousand, twenty".