201657641 has 4 divisors (see below), whose sum is σ = 202784400. Its totient is φ = 200530884.

The previous prime is 201657637. The next prime is 201657661. The reversal of 201657641 is 146756102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 146756102 = 2 ⋅73378051.

It is a cyclic number.

It is not a de Polignac number, because 201657641 - 2² = 201657637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201657598 and 201657607.

It is not an unprimeable number, because it can be changed into a prime (201657661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 563111 + ... + 563468.

It is an arithmetic number, because the mean of its divisors is an integer number (50696100).

Almost surely, 2^201657641 is an apocalyptic number.

It is an amenable number.

201657641 is a deficient number, since it is larger than the sum of its proper divisors (1126759).

201657641 is a wasteful number, since it uses less digits than its factorization.

201657641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1126758.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 201657641 is about 14200.6211483864. The cubic root of 201657641 is about 586.4147616792.

The spelling of 201657641 in words is "two hundred one million, six hundred fifty-seven thousand, six hundred forty-one".