8561780640 has 144 divisors (see below), whose sum is σ = 33390983808. Its totient is φ = 1956976128.

The previous prime is 8561780629. The next prime is 8561780653. The reversal of 8561780640 is 460871658.

It is a happy number.

8561780640 is a `hidden beast` number, since 8 + 561 + 7 + 80 + 6 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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 23 ways as a sum of consecutive naturals, for example, 414612 + ... + 434771.

It is an arithmetic number, because the mean of its divisors is an integer number (231881832).

Almost surely, 2^8561780640 is an apocalyptic number.

8561780640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8561780640 is an abundant number, since it is smaller than the sum of its proper divisors (24829203168).

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

8561780640 is a wasteful number, since it uses less digits than its factorization.

8561780640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 849411 (or 849400 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 8561780640 is about 92529.8905219281. The cubic root of 8561780640 is about 2045.7600759820.

The spelling of 8561780640 in words is "eight billion, five hundred sixty-one million, seven hundred eighty thousand, six hundred forty".