161200621 has 4 divisors (see below), whose sum is σ = 161294332. Its totient is φ = 161106912.

The previous prime is 161200607. The next prime is 161200631. The reversal of 161200621 is 126002161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34975396 + 126225225 = 5914^2 + 11235^2 .

It is a cyclic number.

It is not a de Polignac number, because 161200621 - 2¹⁷ = 161069549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161200631) 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, 44226 + ... + 47731.

It is an arithmetic number, because the mean of its divisors is an integer number (40323583).

Almost surely, 2^161200621 is an apocalyptic number.

It is an amenable number.

161200621 is a deficient number, since it is larger than the sum of its proper divisors (93711).

161200621 is an equidigital number, since it uses as much as digits as its factorization.

161200621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93710.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 161200621 is about 12696.4806541025. The cubic root of 161200621 is about 544.2380520372.

Adding to 161200621 its reverse (126002161), we get a palindrome (287202782).

The spelling of 161200621 in words is "one hundred sixty-one million, two hundred thousand, six hundred twenty-one".