7740561861 has 30 divisors (see below), whose sum is σ = 11500376030. Its totient is φ = 5016559392.

The previous prime is 7740561859. The next prime is 7740561863. The reversal of 7740561861 is 1681650477.

7740561861 is a `hidden beast` number, since 7 + 7 + 4 + 0 + 561 + 86 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (7740561859) and next prime (7740561863).

It can be written as a sum of positive squares in 5 ways, for example, as 211702500 + 7528859361 = 14550^2 + 86769^2 .

It is not a de Polignac number, because 7740561861 - 2¹ = 7740561859 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7740561863) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 71014275 + ... + 71014383.

Almost surely, 2^7740561861 is an apocalyptic number.

It is an amenable number.

7740561861 is a deficient number, since it is larger than the sum of its proper divisors (3759814169).

7740561861 is an frugal number, since it uses more digits than its factorization.

7740561861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The square root of 7740561861 is about 87980.4629505892. The cubic root of 7740561861 is about 1978.1421423580.

The spelling of 7740561861 in words is "seven billion, seven hundred forty million, five hundred sixty-one thousand, eight hundred sixty-one".