151121021 has 4 divisors (see below), whose sum is σ = 152819100. Its totient is φ = 149422944.

The previous prime is 151121011. The next prime is 151121081. The reversal of 151121021 is 120121151.

151121021 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 45832900 + 105288121 = 6770^2 + 10261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-151121021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 151120987 and 151121005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151121011) 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, 848906 + ... + 849083.

It is an arithmetic number, because the mean of its divisors is an integer number (38204775).

Almost surely, 2^151121021 is an apocalyptic number.

It is an amenable number.

151121021 is a deficient number, since it is larger than the sum of its proper divisors (1698079).

151121021 is an equidigital number, since it uses as much as digits as its factorization.

151121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1698078.

The product of its (nonzero) digits is 20, while the sum is 14.

The square root of 151121021 is about 12293.1290158364. The cubic root of 151121021 is about 532.6496259348.

Adding to 151121021 its reverse (120121151), we get a palindrome (271242172).

The spelling of 151121021 in words is "one hundred fifty-one million, one hundred twenty-one thousand, twenty-one".