161256630340 has 48 divisors (see below), whose sum is σ = 377263540080. Its totient is φ = 57487772160.

The previous prime is 161256630323. The next prime is 161256630341. The reversal of 161256630340 is 43036652161.

It can be written as a sum of positive squares in 8 ways, for example, as 12828280644 + 148428349696 = 113262^2 + 385264^2 .

It is a super-2 number, since 2×161256630340² (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 161256630340.

It is not an unprimeable number, because it can be changed into a prime (161256630341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10685871 + ... + 10700950.

It is an arithmetic number, because the mean of its divisors is an integer number (7859657085).

Almost surely, 2^161256630340 is an apocalyptic number.

161256630340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161256630340 is an abundant number, since it is smaller than the sum of its proper divisors (216006909740).

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

161256630340 is a wasteful number, since it uses less digits than its factorization.

161256630340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21386872 (or 21386870 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 161256630340 in words is "one hundred sixty-one billion, two hundred fifty-six million, six hundred thirty thousand, three hundred forty".