1001021020 has 24 divisors (see below), whose sum is σ = 2102806944. Its totient is φ = 400282176.

The previous prime is 1001020997. The next prime is 1001021057. The reversal of 1001021020 is 201201001.

It is a junction number, because it is equal to n+sod(n) for n = 1001020994 and 1001021012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82249 + ... + 93631.

It is an arithmetic number, because the mean of its divisors is an integer number (87616956).

Almost surely, 2^1001021020 is an apocalyptic number.

1001021020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1001021020 is an abundant number, since it is smaller than the sum of its proper divisors (1101785924).

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

1001021020 is a wasteful number, since it uses less digits than its factorization.

1001021020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15789 (or 15787 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 1001021020 is about 31638.9162266978. The cubic root of 1001021020 is about 1000.3402242343.

Adding to 1001021020 its reverse (201201001), we get a palindrome (1202222021).

The spelling of 1001021020 in words is "one billion, one million, twenty-one thousand, twenty".