1011012506261 has 4 divisors (see below), whose sum is σ = 1011014544192. Its totient is φ = 1011010468332.

The previous prime is 1011012506237. The next prime is 1011012506291. The reversal of 1011012506261 is 1626052101101.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1011012506261 is a prime.

It is a super-2 number, since 2×1011012506261² (a number of 25 digits) contains 22 as substring.

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 1011012506261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011012506291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 261746 + ... + 1445868.

It is an arithmetic number, because the mean of its divisors is an integer number (252753636048).

Almost surely, 2^{1011012506261} is an apocalyptic number.

It is an amenable number.

1011012506261 is a deficient number, since it is larger than the sum of its proper divisors (2037931).

1011012506261 is an equidigital number, since it uses as much as digits as its factorization.

1011012506261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2037930.

The product of its (nonzero) digits is 720, while the sum is 26.

Adding to 1011012506261 its reverse (1626052101101), we get a palindrome (2637064607362).

The spelling of 1011012506261 in words is "one trillion, eleven billion, twelve million, five hundred six thousand, two hundred sixty-one".