151620001661 has 4 divisors (see below), whose sum is σ = 155318050524. Its totient is φ = 147921952800.

The previous prime is 151620001657. The next prime is 151620001699. The reversal of 151620001661 is 166100026151.

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 91381662436 + 60238339225 = 302294^2 + 245435^2 .

It is a cyclic number.

It is not a de Polignac number, because 151620001661 - 2² = 151620001657 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 (151620001261) 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, 1849024370 + ... + 1849024451.

It is an arithmetic number, because the mean of its divisors is an integer number (38829512631).

Almost surely, 2^151620001661 is an apocalyptic number.

It is an amenable number.

151620001661 is a deficient number, since it is larger than the sum of its proper divisors (3698048863).

151620001661 is an equidigital number, since it uses as much as digits as its factorization.

151620001661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3698048862.

The product of its (nonzero) digits is 2160, while the sum is 29.

The spelling of 151620001661 in words is "one hundred fifty-one billion, six hundred twenty million, one thousand, six hundred sixty-one".