1221401403431 has 16 divisors (see below), whose sum is σ = 1355552876160. Its totient is φ = 1091181542880.

The previous prime is 1221401403419. The next prime is 1221401403437. The reversal of 1221401403431 is 1343041041221.

It is not a de Polignac number, because 1221401403431 - 2¹⁴ = 1221401387047 is a prime.

It is a super-2 number, since 2×1221401403431² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221401403431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221401403437) 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, 1668836 + ... + 2286441.

It is an arithmetic number, because the mean of its divisors is an integer number (84722054760).

Almost surely, 2^{1221401403431} is an apocalyptic number.

1221401403431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221401403431 is a deficient number, since it is larger than the sum of its proper divisors (134151472729).

1221401403431 is a wasteful number, since it uses less digits than its factorization.

1221401403431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3955774.

The product of its (nonzero) digits is 2304, while the sum is 26.

Adding to 1221401403431 its reverse (1343041041221), we get a palindrome (2564442444652).

The spelling of 1221401403431 in words is "one trillion, two hundred twenty-one billion, four hundred one million, four hundred three thousand, four hundred thirty-one".