1311201021 has 32 divisors (see below), whose sum is σ = 1945495552. Its totient is φ = 780373440.

The previous prime is 1311201013. The next prime is 1311201061. The reversal of 1311201021 is 1201021131.

It is not a de Polignac number, because 1311201021 - 2³ = 1311201013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1311200988 and 1311201006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311201011) 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 31 ways as a sum of consecutive naturals, for example, 168936 + ... + 176526.

It is an arithmetic number, because the mean of its divisors is an integer number (60796736).

Almost surely, 2^1311201021 is an apocalyptic number.

It is an amenable number.

1311201021 is a deficient number, since it is larger than the sum of its proper divisors (634294531).

1311201021 is a wasteful number, since it uses less digits than its factorization.

1311201021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7753.

The product of its (nonzero) digits is 12, while the sum is 12.

The square root of 1311201021 is about 36210.5098141410. The cubic root of 1311201021 is about 1094.5184655312.

Adding to 1311201021 its reverse (1201021131), we get a palindrome (2512222152).

It can be divided in two parts, 131 and 1201021, that multiplied together give a palindrome (157333751).

The spelling of 1311201021 in words is "one billion, three hundred eleven million, two hundred one thousand, twenty-one".