40561297920 has 720 divisors, whose sum is σ = 166115787552. Its totient is φ = 9067069440.

The previous prime is 40561297919. The next prime is 40561297943. The reversal of 40561297920 is 2979216504.

40561297920 is a `hidden beast` number, since 4 + 0 + 5 + 612 + 9 + 7 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 42830887 + ... + 42831833.

Almost surely, 2^40561297920 is an apocalyptic number.

40561297920 is a gapful number since it is divisible by the number (40) 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 40561297920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83057893776).

40561297920 is an abundant number, since it is smaller than the sum of its proper divisors (125554489632).

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

40561297920 is a wasteful number, since it uses less digits than its factorization.

40561297920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013 (or 981 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 40561297920 in words is "forty billion, five hundred sixty-one million, two hundred ninety-seven thousand, nine hundred twenty".