1311323031021 has 16 divisors (see below), whose sum is σ = 1830204825984. Its totient is φ = 833568103104.

The previous prime is 1311323031017. The next prime is 1311323031041. The reversal of 1311323031021 is 1201303231131.

It is a happy number.

It is not a de Polignac number, because 1311323031021 - 2² = 1311323031017 is a prime.

It is a super-2 number, since 2×1311323031021² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311323031041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29953966 + ... + 29997711.

It is an arithmetic number, because the mean of its divisors is an integer number (114387801624).

Almost surely, 2^{1311323031021} is an apocalyptic number.

It is an amenable number.

1311323031021 is a deficient number, since it is larger than the sum of its proper divisors (518881794963).

1311323031021 is a wasteful number, since it uses less digits than its factorization.

1311323031021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59952020.

The product of its (nonzero) digits is 324, while the sum is 21.

Adding to 1311323031021 its reverse (1201303231131), we get a palindrome (2512626262152).

The spelling of 1311323031021 in words is "one trillion, three hundred eleven billion, three hundred twenty-three million, thirty-one thousand, twenty-one".