1221055125401 has 4 divisors (see below), whose sum is σ = 1221421922100. Its totient is φ = 1220688328704.

The previous prime is 1221055125373. The next prime is 1221055125431. The reversal of 1221055125401 is 1045215501221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 670557903376 + 550497222025 = 818876^2 + 741955^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221055125401 - 2¹⁸ = 1221054863257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1221055125431) 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, 183393356 + ... + 183400013.

It is an arithmetic number, because the mean of its divisors is an integer number (305355480525).

Almost surely, 2^{1221055125401} is an apocalyptic number.

It is an amenable number.

1221055125401 is a deficient number, since it is larger than the sum of its proper divisors (366796699).

1221055125401 is an equidigital number, since it uses as much as digits as its factorization.

1221055125401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366796698.

The product of its (nonzero) digits is 4000, while the sum is 29.

The spelling of 1221055125401 in words is "one trillion, two hundred twenty-one billion, fifty-five million, one hundred twenty-five thousand, four hundred one".