265351663621021 has 4 divisors (see below), whose sum is σ = 270997443698112. Its totient is φ = 259705883543932.

The previous prime is 265351663621003. The next prime is 265351663621043. The reversal of 265351663621021 is 120126366153562.

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 265351663621021 - 2⁷ = 265351663620893 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 (265351663021021) 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, 2822890038475 + ... + 2822890038568.

It is an arithmetic number, because the mean of its divisors is an integer number (67749360924528).

Almost surely, 2^{265351663621021} is an apocalyptic number.

It is an amenable number.

265351663621021 is a deficient number, since it is larger than the sum of its proper divisors (5645780077091).

265351663621021 is an equidigital number, since it uses as much as digits as its factorization.

265351663621021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5645780077090.

The product of its (nonzero) digits is 2332800, while the sum is 49.

The spelling of 265351663621021 in words is "two hundred sixty-five trillion, three hundred fifty-one billion, six hundred sixty-three million, six hundred twenty-one thousand, twenty-one".