161661551461410 has 512 divisors, whose sum is σ = 544233744875520. Its totient is φ = 29642328576000.

The previous prime is 161661551461373. The next prime is 161661551461469. The reversal of 161661551461410 is 14164155166161.

It is a super-2 number, since 2×161661551461410² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161661551461410.

It is an unprimeable number.

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 255 ways as a sum of consecutive naturals, for example, 87038899 + ... + 88876841.

It is an arithmetic number, because the mean of its divisors is an integer number (1062956532960).

Almost surely, 2^{161661551461410} is an apocalyptic number.

161661551461410 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161661551461410, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (272116872437760).

161661551461410 is an abundant number, since it is smaller than the sum of its proper divisors (382572193414110).

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

161661551461410 is a wasteful number, since it uses less digits than its factorization.

161661551461410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1838114.

The product of its (nonzero) digits is 518400, while the sum is 48.

The spelling of 161661551461410 in words is "one hundred sixty-one trillion, six hundred sixty-one billion, five hundred fifty-one million, four hundred sixty-one thousand, four hundred ten".