1012131521 has 4 divisors (see below), whose sum is σ = 1018924500. Its totient is φ = 1005338544.

The previous prime is 1012131517. The next prime is 1012131529. The reversal of 1012131521 is 1251312101.

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 310464400 + 701667121 = 17620^2 + 26489^2 .

It is a cyclic number.

It is not a de Polignac number, because 1012131521 - 2² = 1012131517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1012131521.

It is not an unprimeable number, because it can be changed into a prime (1012131529) 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, 3396266 + ... + 3396563.

It is an arithmetic number, because the mean of its divisors is an integer number (254731125).

Almost surely, 2^1012131521 is an apocalyptic number.

It is an amenable number.

1012131521 is a deficient number, since it is larger than the sum of its proper divisors (6792979).

1012131521 is an equidigital number, since it uses as much as digits as its factorization.

1012131521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6792978.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 1012131521 is about 31814.0145376216. The cubic root of 1012131521 is about 1004.0275970177.

Adding to 1012131521 its reverse (1251312101), we get a palindrome (2263443622).

The spelling of 1012131521 in words is "one billion, twelve million, one hundred thirty-one thousand, five hundred twenty-one".