1561943898820 has 24 divisors (see below), whose sum is σ = 3283780175424. Its totient is φ = 624073180896.

The previous prime is 1561943898793. The next prime is 1561943898859. The reversal of 1561943898820 is 288983491651.

It is a happy number.

It is a super-2 number, since 2×1561943898820² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44005482 + ... + 44040961.

It is an arithmetic number, because the mean of its divisors is an integer number (136824173976).

Almost surely, 2^{1561943898820} is an apocalyptic number.

1561943898820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561943898820 is an abundant number, since it is smaller than the sum of its proper divisors (1721836276604).

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

1561943898820 is a wasteful number, since it uses less digits than its factorization.

1561943898820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88047339 (or 88047337 counting only the distinct ones).

The product of its (nonzero) digits is 29859840, while the sum is 64.

The spelling of 1561943898820 in words is "one trillion, five hundred sixty-one billion, nine hundred forty-three million, eight hundred ninety-eight thousand, eight hundred twenty".