265643144023551 has 32 divisors (see below), whose sum is σ = 429749766724608. Its totient is φ = 142483879733760.

The previous prime is 265643144023501. The next prime is 265643144023601. The reversal of 265643144023551 is 155320441346562.

It is an interprime number because it is at equal distance from previous prime (265643144023501) and next prime (265643144023601).

It is not a de Polignac number, because 265643144023551 - 2¹⁰ = 265643144022527 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a junction number, because it is equal to n+sod(n) for n = 265643144023494 and 265643144023503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265643144023501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 997317835 + ... + 997584156.

It is an arithmetic number, because the mean of its divisors is an integer number (13429680210144).

Almost surely, 2^{265643144023551} is an apocalyptic number.

265643144023551 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

265643144023551 is a deficient number, since it is larger than the sum of its proper divisors (164106622701057).

265643144023551 is a wasteful number, since it uses less digits than its factorization.

265643144023551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1994902391.

The product of its (nonzero) digits is 10368000, while the sum is 51.

The spelling of 265643144023551 in words is "two hundred sixty-five trillion, six hundred forty-three billion, one hundred forty-four million, twenty-three thousand, five hundred fifty-one".