621553444226261 has 4 divisors (see below), whose sum is σ = 621894395102592. Its totient is φ = 621212493349932.

The previous prime is 621553444226233. The next prime is 621553444226389. The reversal of 621553444226261 is 162622444355126.

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 621553444226261 - 2¹⁴ = 621553444209877 is a prime.

It is a super-4 number, since 4×621553444226261⁴ (a number of 60 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621553444225261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170475435431 + ... + 170475439076.

It is an arithmetic number, because the mean of its divisors is an integer number (155473598775648).

Almost surely, 2^{621553444226261} is an apocalyptic number.

It is an amenable number.

621553444226261 is a deficient number, since it is larger than the sum of its proper divisors (340950876331).

621553444226261 is a wasteful number, since it uses less digits than its factorization.

621553444226261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340950876330.

The product of its digits is 16588800, while the sum is 53.

The spelling of 621553444226261 in words is "six hundred twenty-one trillion, five hundred fifty-three billion, four hundred forty-four million, two hundred twenty-six thousand, two hundred sixty-one".