251620454543 has 4 divisors (see below), whose sum is σ = 251629565688. Its totient is φ = 251611343400.

The previous prime is 251620454479. The next prime is 251620454573. The reversal of 251620454543 is 345454026152.

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

It is a cyclic number.

It is not a de Polignac number, because 251620454543 - 2⁶ = 251620454479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251620454543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251620454573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4514021 + ... + 4569422.

It is an arithmetic number, because the mean of its divisors is an integer number (62907391422).

Almost surely, 2^251620454543 is an apocalyptic number.

251620454543 is a deficient number, since it is larger than the sum of its proper divisors (9111145).

251620454543 is an equidigital number, since it uses as much as digits as its factorization.

251620454543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9111144.

The product of its (nonzero) digits is 576000, while the sum is 41.

The spelling of 251620454543 in words is "two hundred fifty-one billion, six hundred twenty million, four hundred fifty-four thousand, five hundred forty-three".