161645023621 has 8 divisors (see below), whose sum is σ = 162983318400. Its totient is φ = 160309234560.

The previous prime is 161645023619. The next prime is 161645023627. The reversal of 161645023621 is 126320546161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161645023621 - 2¹ = 161645023619 is a prime.

It is a super-2 number, since 2×161645023621² (a number of 23 digits) 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 (161645023627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 496765 + ... + 755026.

It is an arithmetic number, because the mean of its divisors is an integer number (20372914800).

Almost surely, 2^161645023621 is an apocalyptic number.

It is an amenable number.

161645023621 is a deficient number, since it is larger than the sum of its proper divisors (1338294779).

161645023621 is a wasteful number, since it uses less digits than its factorization.

161645023621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1252859.

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 161645023621 its reverse (126320546161), we get a palindrome (287965569782).

The spelling of 161645023621 in words is "one hundred sixty-one billion, six hundred forty-five million, twenty-three thousand, six hundred twenty-one".