151221551557 has 4 divisors (see below), whose sum is σ = 155308620556. Its totient is φ = 147134482560.

The previous prime is 151221551549. The next prime is 151221551563. The reversal of 151221551557 is 755155122151.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 755155122151 = 19 ⋅39745006429.

It can be written as a sum of positive squares in 2 ways, for example, as 132331523076 + 18890028481 = 363774^2 + 137441^2 .

It is a cyclic number.

It is not a de Polignac number, because 151221551557 - 2³ = 151221551549 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 (151221551527) 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, 2043534444 + ... + 2043534517.

It is an arithmetic number, because the mean of its divisors is an integer number (38827155139).

Almost surely, 2^151221551557 is an apocalyptic number.

It is an amenable number.

151221551557 is a deficient number, since it is larger than the sum of its proper divisors (4087068999).

151221551557 is an equidigital number, since it uses as much as digits as its factorization.

151221551557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4087068998.

The product of its digits is 87500, while the sum is 40.

The spelling of 151221551557 in words is "one hundred fifty-one billion, two hundred twenty-one million, five hundred fifty-one thousand, five hundred fifty-seven".