201001001220 has 72 divisors (see below), whose sum is σ = 610042556760. Its totient is φ = 53570419200.

The previous prime is 201001001183. The next prime is 201001001237. The reversal of 201001001220 is 22100100102.

It can be written as a sum of positive squares in 4 ways, for example, as 19223267904 + 181777733316 = 138648^2 + 426354^2 .

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

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, 14166 + ... + 634194.

Almost surely, 2^201001001220 is an apocalyptic number.

201001001220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201001001220 is an abundant number, since it is smaller than the sum of its proper divisors (409041555540).

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

201001001220 is a wasteful number, since it uses less digits than its factorization.

201001001220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621845 (or 621840 counting only the distinct ones).

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

Adding to 201001001220 its reverse (22100100102), we get a palindrome (223101101322).

The spelling of 201001001220 in words is "two hundred one billion, one million, one thousand, two hundred twenty".