50001661 has 4 divisors (see below), whose sum is σ = 50116000. Its totient is φ = 49887324.

The previous prime is 50001649. The next prime is 50001683. The reversal of 50001661 is 16610005.

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: 16610005 = 5 ⋅3322001.

It is a cyclic number.

It is not a de Polignac number, because 50001661 - 2⁷ = 50001533 is a prime.

It is a super-2 number, since 2×50001661² = 5000332205517842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (50001691) 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, 56511 + ... + 57388.

It is an arithmetic number, because the mean of its divisors is an integer number (12529000).

Almost surely, 2^50001661 is an apocalyptic number.

It is an amenable number.

50001661 is a deficient number, since it is larger than the sum of its proper divisors (114339).

50001661 is a wasteful number, since it uses less digits than its factorization.

50001661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114338.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 50001661 is about 7071.1852613264. The cubic root of 50001661 is about 368.4072292697.

Adding to 50001661 its reverse (16610005), we get a palindrome (66611666).

The spelling of 50001661 in words is "fifty million, one thousand, six hundred sixty-one".