151632221 has 4 divisors (see below), whose sum is σ = 163296252. Its totient is φ = 139968192.

The previous prime is 151632203. The next prime is 151632223. The reversal of 151632221 is 122236151.

151632221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 51912025 + 99720196 = 7205^2 + 9986^2 .

It is not a de Polignac number, because 151632221 - 2¹⁸ = 151370077 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 (151632223) 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, 5831996 + ... + 5832021.

It is an arithmetic number, because the mean of its divisors is an integer number (40824063).

Almost surely, 2^151632221 is an apocalyptic number.

It is an amenable number.

151632221 is a deficient number, since it is larger than the sum of its proper divisors (11664031).

151632221 is a wasteful number, since it uses less digits than its factorization.

151632221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11664030.

The product of its digits is 720, while the sum is 23.

The square root of 151632221 is about 12313.9035646703. The cubic root of 151632221 is about 533.2495513792.

Adding to 151632221 its reverse (122236151), we get a palindrome (273868372).

The spelling of 151632221 in words is "one hundred fifty-one million, six hundred thirty-two thousand, two hundred twenty-one".