1231404121 has 4 divisors (see below), whose sum is σ = 1232065552. Its totient is φ = 1230742692.

The previous prime is 1231404113. The next prime is 1231404131. The reversal of 1231404121 is 1214041321.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1214041321 = 131 ⋅9267491.

It is a cyclic number.

It is not a de Polignac number, because 1231404121 - 2³ = 1231404113 is a prime.

It is a super-2 number, since 2×1231404121² = 3032712218431565282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231404131) 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, 327915 + ... + 331648.

It is an arithmetic number, because the mean of its divisors is an integer number (308016388).

Almost surely, 2^1231404121 is an apocalyptic number.

It is an amenable number.

1231404121 is a deficient number, since it is larger than the sum of its proper divisors (661431).

1231404121 is an equidigital number, since it uses as much as digits as its factorization.

1231404121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661430.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 1231404121 is about 35091.3681836431. The cubic root of 1231404121 is about 1071.8488201195.

Adding to 1231404121 its reverse (1214041321), we get a palindrome (2445445442).

The spelling of 1231404121 in words is "one billion, two hundred thirty-one million, four hundred four thousand, one hundred twenty-one".