161307262621 has 4 divisors (see below), whose sum is σ = 164350795932. Its totient is φ = 158263729312.

The previous prime is 161307262609. The next prime is 161307262637. The reversal of 161307262621 is 126262703161.

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 61189443225 + 100117819396 = 247365^2 + 316414^2 .

It is a cyclic number.

It is not a de Polignac number, because 161307262621 - 2³⁷ = 23868309149 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 (161307262021) 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, 1521766576 + ... + 1521766681.

It is an arithmetic number, because the mean of its divisors is an integer number (41087698983).

Almost surely, 2^161307262621 is an apocalyptic number.

It is an amenable number.

161307262621 is a deficient number, since it is larger than the sum of its proper divisors (3043533311).

161307262621 is an equidigital number, since it uses as much as digits as its factorization.

161307262621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043533310.

The product of its (nonzero) digits is 36288, while the sum is 37.

Adding to 161307262621 its reverse (126262703161), we get a palindrome (287569965782).

The spelling of 161307262621 in words is "one hundred sixty-one billion, three hundred seven million, two hundred sixty-two thousand, six hundred twenty-one".