201521020 has 24 divisors (see below), whose sum is σ = 424767168. Its totient is φ = 80308800.

The previous prime is 201520967. The next prime is 201521039. The reversal of 201521020 is 20125102.

It is a super-2 number, since 2×201521020² = 81221443003680800, which contains 22 as substring.

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, 13171 + ... + 24010.

It is an arithmetic number, because the mean of its divisors is an integer number (17698632).

Almost surely, 2^201521020 is an apocalyptic number.

201521020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201521020 is an abundant number, since it is smaller than the sum of its proper divisors (223246148).

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

201521020 is a wasteful number, since it uses less digits than its factorization.

201521020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37461 (or 37459 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 201521020 is about 14195.8099451916. The cubic root of 201521020 is about 586.2823017497.

Adding to 201521020 its reverse (20125102), we get a palindrome (221646122).

The spelling of 201521020 in words is "two hundred one million, five hundred twenty-one thousand, twenty".