161620434440 has 16 divisors (see below), whose sum is σ = 363645977580. Its totient is φ = 64648173760.

The previous prime is 161620434433. The next prime is 161620434461. The reversal of 161620434440 is 44434026161.

It can be written as a sum of positive squares in 2 ways, for example, as 157080639556 + 4539794884 = 396334^2 + 67378^2 .

It is a super-2 number, since 2×161620434440² (a number of 23 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 161620434440.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2020255391 + ... + 2020255470.

Almost surely, 2^161620434440 is an apocalyptic number.

161620434440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161620434440 is an abundant number, since it is smaller than the sum of its proper divisors (202025543140).

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

161620434440 is a wasteful number, since it uses less digits than its factorization.

161620434440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4040510872 (or 4040510868 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 35.

The spelling of 161620434440 in words is "one hundred sixty-one billion, six hundred twenty million, four hundred thirty-four thousand, four hundred forty".