1221055125431 has 2 divisors, whose sum is σ = 1221055125432. Its totient is φ = 1221055125430.

The previous prime is 1221055125373. The next prime is 1221055125439. The reversal of 1221055125431 is 1345215501221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221055125431 - 2¹⁰ = 1221055124407 is a prime.

It is a super-2 number, since 2×1221055125431² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221055125439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610527562715 + 610527562716.

It is an arithmetic number, because the mean of its divisors is an integer number (610527562716).

Almost surely, 2^{1221055125431} is an apocalyptic number.

1221055125431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221055125431 is an equidigital number, since it uses as much as digits as its factorization.

1221055125431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12000, while the sum is 32.

The spelling of 1221055125431 in words is "one trillion, two hundred twenty-one billion, fifty-five million, one hundred twenty-five thousand, four hundred thirty-one".