1561775040 has 896 divisors, whose sum is σ = 7022592000. Its totient is φ = 325140480.

The previous prime is 1561775011. The next prime is 1561775051. The reversal of 1561775040 is 405771651.

1561775040 is a `hidden beast` number, since 1 + 561 + 7 + 7 + 50 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1561774986 and 1561775004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 50379825 + ... + 50379855.

Almost surely, 2^1561775040 is an apocalyptic number.

1561775040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561775040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3511296000).

1561775040 is an abundant number, since it is smaller than the sum of its proper divisors (5460816960).

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

1561775040 is a wasteful number, since it uses less digits than its factorization.

1561775040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The square root of 1561775040 is about 39519.2995889350. The cubic root of 1561775040 is about 1160.2177157742.

The spelling of 1561775040 in words is "one billion, five hundred sixty-one million, seven hundred seventy-five thousand, forty".