1621601236253 has 4 divisors (see below), whose sum is σ = 1706948669760. Its totient is φ = 1536253802748.

The previous prime is 1621601236147. The next prime is 1621601236301. The reversal of 1621601236253 is 3526321061261.

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.

It is a cyclic number.

It is not a de Polignac number, because 1621601236253 - 2²⁰ = 1621600187677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621601236753) 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, 42673716725 + ... + 42673716762.

It is an arithmetic number, because the mean of its divisors is an integer number (426737167440).

Almost surely, 2^{1621601236253} is an apocalyptic number.

It is an amenable number.

1621601236253 is a deficient number, since it is larger than the sum of its proper divisors (85347433507).

1621601236253 is an equidigital number, since it uses as much as digits as its factorization.

1621601236253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85347433506.

The product of its (nonzero) digits is 77760, while the sum is 38.

The spelling of 1621601236253 in words is "one trillion, six hundred twenty-one billion, six hundred one million, two hundred thirty-six thousand, two hundred fifty-three".