1561640554340 has 24 divisors (see below), whose sum is σ = 3311284441920. Its totient is φ = 618591597408.

The previous prime is 1561640554339. The next prime is 1561640554373. The reversal of 1561640554340 is 434550461651.

It is a junction number, because it is equal to n+sod(n) for n = 1561640554291 and 1561640554300.

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, 379036910 + ... + 379041029.

It is an arithmetic number, because the mean of its divisors is an integer number (137970185080).

Almost surely, 2^{1561640554340} is an apocalyptic number.

1561640554340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561640554340 is an abundant number, since it is smaller than the sum of its proper divisors (1749643887580).

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

1561640554340 is a wasteful number, since it uses less digits than its factorization.

1561640554340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758078051 (or 758078049 counting only the distinct ones).

The product of its (nonzero) digits is 864000, while the sum is 44.

The spelling of 1561640554340 in words is "one trillion, five hundred sixty-one billion, six hundred forty million, five hundred fifty-four thousand, three hundred forty".