151661106221 has 8 divisors (see below), whose sum is σ = 152378916984. Its totient is φ = 150944657920.

The previous prime is 151661106187. The next prime is 151661106241. The reversal of 151661106221 is 122601166151.

It can be written as a sum of positive squares in 4 ways, for example, as 4968276196 + 146692830025 = 70486^2 + 383005^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-151661106221 is a prime.

It is a super-2 number, since 2×151661106221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151661106241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117116 + ... + 563061.

It is an arithmetic number, because the mean of its divisors is an integer number (19047364623).

Almost surely, 2^151661106221 is an apocalyptic number.

It is an amenable number.

151661106221 is a deficient number, since it is larger than the sum of its proper divisors (717810763).

151661106221 is an equidigital number, since it uses as much as digits as its factorization.

151661106221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681231.

The product of its (nonzero) digits is 4320, while the sum is 32.

The spelling of 151661106221 in words is "one hundred fifty-one billion, six hundred sixty-one million, one hundred six thousand, two hundred twenty-one".