1231121001000 has 128 divisors (see below), whose sum is σ = 4190288319360. Its totient is φ = 298453568000.

The previous prime is 1231121000999. The next prime is 1231121001001. The reversal of 1231121001000 is 1001211321.

It is an interprime number because it is at equal distance from previous prime (1231121000999) and next prime (1231121001001).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (1231121001001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18620349 + ... + 18686348.

It is an arithmetic number, because the mean of its divisors is an integer number (32736627495).

Almost surely, 2^{1231121001000} is an apocalyptic number.

1231121001000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231121001000 is an abundant number, since it is smaller than the sum of its proper divisors (2959167318360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231121001000 is a wasteful number, since it uses less digits than its factorization.

1231121001000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37306732 (or 37306718 counting only the distinct ones).

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

Adding to 1231121001000 its reverse (1001211321), we get a palindrome (1232122212321).

The spelling of 1231121001000 in words is "one trillion, two hundred thirty-one billion, one hundred twenty-one million, one thousand".