201663642420 has 36 divisors (see below), whose sum is σ = 611713049220. Its totient is φ = 53776971264.

The previous prime is 201663642283. The next prime is 201663642457. The reversal of 201663642420 is 24246366102.

201663642420 is a `hidden beast` number, since 2 + 0 + 1 + 6 + 6 + 3 + 642 + 4 + 2 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 32214506256 + 169449136164 = 179484^2 + 411642^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 560176605 + ... + 560176964.

It is an arithmetic number, because the mean of its divisors is an integer number (16992029145).

Almost surely, 2^201663642420 is an apocalyptic number.

201663642420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201663642420 is an abundant number, since it is smaller than the sum of its proper divisors (410049406800).

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

201663642420 is a wasteful number, since it uses less digits than its factorization.

201663642420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120353584 (or 1120353579 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The spelling of 201663642420 in words is "two hundred one billion, six hundred sixty-three million, six hundred forty-two thousand, four hundred twenty".