201531660 has 48 divisors (see below), whose sum is σ = 615589632. Its totient is φ = 48856000.

The previous prime is 201531653. The next prime is 201531661. The reversal of 201531660 is 66135102.

It is a self number, because there is not a number n which added to its sum of digits gives 201531660.

It is not an unprimeable number, because it can be changed into a prime (201531661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152016 + ... + 153335.

It is an arithmetic number, because the mean of its divisors is an integer number (12824784).

Almost surely, 2^201531660 is an apocalyptic number.

201531660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201531660 is an abundant number, since it is smaller than the sum of its proper divisors (414057972).

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

201531660 is a wasteful number, since it uses less digits than its factorization.

201531660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305374 (or 305372 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 201531660 is about 14196.1846987139. The cubic root of 201531660 is about 586.2926198362.

Adding to 201531660 its reverse (66135102), we get a palindrome (267666762).

The spelling of 201531660 in words is "two hundred one million, five hundred thirty-one thousand, six hundred sixty".