7736256661 has 6 divisors (see below), whose sum is σ = 8999319030. Its totient is φ = 6631077096.

The previous prime is 7736256653. The next prime is 7736256673. The reversal of 7736256661 is 1666526377.

It can be written as a sum of positive squares in only one way, i.e., 6574128561 + 1162128100 = 81081^2 + 34090^2 .

It is not a de Polignac number, because 7736256661 - 2³ = 7736256653 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49), and also a Moran number because the ratio is a prime number: 157882789 = 7736256661 / (7 + 7 + 3 + 6 + 2 + 5 + 6 + 6 + 6 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7736256641) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 78941346 + ... + 78941443.

It is an arithmetic number, because the mean of its divisors is an integer number (1499886505).

Almost surely, 2^7736256661 is an apocalyptic number.

It is an amenable number.

7736256661 is a deficient number, since it is larger than the sum of its proper divisors (1263062369).

7736256661 is a wasteful number, since it uses less digits than its factorization.

7736256661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157882803 (or 157882796 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 49.

The square root of 7736256661 is about 87955.9927520575. The cubic root of 7736256661 is about 1977.7753353537.

The spelling of 7736256661 in words is "seven billion, seven hundred thirty-six million, two hundred fifty-six thousand, six hundred sixty-one".