7561609781 has 8 divisors (see below), whose sum is σ = 8249689728. Its totient is φ = 6873640000.

The previous prime is 7561609777. The next prime is 7561609801. The reversal of 7561609781 is 1879061657.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7561609781 - 2² = 7561609777 is a prime.

It is a super-2 number, since 2×7561609781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7561609681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 192356 + ... + 228306.

It is an arithmetic number, because the mean of its divisors is an integer number (1031211216).

Almost surely, 2^7561609781 is an apocalyptic number.

It is an amenable number.

7561609781 is a deficient number, since it is larger than the sum of its proper divisors (688079947).

7561609781 is a wasteful number, since it uses less digits than its factorization.

7561609781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55083.

The product of its (nonzero) digits is 635040, while the sum is 50.

The square root of 7561609781 is about 86957.5171046184. The cubic root of 7561609781 is about 1962.7790804701.

The spelling of 7561609781 in words is "seven billion, five hundred sixty-one million, six hundred nine thousand, seven hundred eighty-one".