1221401031 has 4 divisors (see below), whose sum is σ = 1628534712. Its totient is φ = 814267352.

The previous prime is 1221401021. The next prime is 1221401053. The reversal of 1221401031 is 1301041221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1301041221 = 3 ⋅433680407.

It is a cyclic number.

It is not a de Polignac number, because 1221401031 - 2⁷ = 1221400903 is a prime.

It is a super-3 number, since 3×1221401031³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 1221401031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221401021) 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, 203566836 + ... + 203566841.

It is an arithmetic number, because the mean of its divisors is an integer number (407133678).

Almost surely, 2^1221401031 is an apocalyptic number.

1221401031 is a deficient number, since it is larger than the sum of its proper divisors (407133681).

1221401031 is an equidigital number, since it uses as much as digits as its factorization.

1221401031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407133680.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1221401031 is about 34948.5483389511. The cubic root of 1221401031 is about 1068.9386018922.

Adding to 1221401031 its reverse (1301041221), we get a palindrome (2522442252).

The spelling of 1221401031 in words is "one billion, two hundred twenty-one million, four hundred one thousand, thirty-one".