7661533815381 has 8 divisors (see below), whose sum is σ = 10215457038784. Its totient is φ = 5107649901120.

The previous prime is 7661533815361. The next prime is 7661533815407. The reversal of 7661533815381 is 1835183351667.

It is a happy number.

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

It is not a de Polignac number, because 7661533815381 - 2⁷ = 7661533815253 is a prime.

It is a super-2 number, since 2×7661533815381² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7661533815361) 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, 9369460 + ... + 10154301.

It is an arithmetic number, because the mean of its divisors is an integer number (1276932129848).

Almost surely, 2^{7661533815381} is an apocalyptic number.

It is an amenable number.

7661533815381 is a deficient number, since it is larger than the sum of its proper divisors (2553923223403).

7661533815381 is a wasteful number, since it uses less digits than its factorization.

7661533815381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19654571.

The product of its digits is 10886400, while the sum is 57.

The spelling of 7661533815381 in words is "seven trillion, six hundred sixty-one billion, five hundred thirty-three million, eight hundred fifteen thousand, three hundred eighty-one".