551661605586 has 240 divisors, whose sum is σ = 1552977074880. Its totient is φ = 145078153920.

The previous prime is 551661605563. The next prime is 551661605591. The reversal of 551661605586 is 685506166155.

It is a happy number.

551661605586 is a `hidden beast` number, since 5 + 5 + 16 + 616 + 0 + 5 + 5 + 8 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 37039201 + ... + 37054091.

It is an arithmetic number, because the mean of its divisors is an integer number (6470737812).

Almost surely, 2^551661605586 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 551661605586, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (776488537440).

551661605586 is an abundant number, since it is smaller than the sum of its proper divisors (1001315469294).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

551661605586 is a wasteful number, since it uses less digits than its factorization.

551661605586 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15291 (or 15275 counting only the distinct ones).

The product of its (nonzero) digits is 6480000, while the sum is 54.

The spelling of 551661605586 in words is "five hundred fifty-one billion, six hundred sixty-one million, six hundred five thousand, five hundred eighty-six".