151206220721 has 4 divisors (see below), whose sum is σ = 151855174692. Its totient is φ = 150557266752.

The previous prime is 151206220709. The next prime is 151206220729. The reversal of 151206220721 is 127022602151.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127022602151 = 83 ⋅1530392797.

It can be written as a sum of positive squares in 2 ways, for example, as 92878657600 + 58327563121 = 304760^2 + 241511^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-151206220721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (151206220729) 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, 324476636 + ... + 324477101.

It is an arithmetic number, because the mean of its divisors is an integer number (37963793673).

Almost surely, 2^151206220721 is an apocalyptic number.

It is an amenable number.

151206220721 is a deficient number, since it is larger than the sum of its proper divisors (648953971).

151206220721 is an equidigital number, since it uses as much as digits as its factorization.

151206220721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648953970.

The product of its (nonzero) digits is 3360, while the sum is 29.

Adding to 151206220721 its reverse (127022602151), we get a palindrome (278228822872).

The spelling of 151206220721 in words is "one hundred fifty-one billion, two hundred six million, two hundred twenty thousand, seven hundred twenty-one".