3954388620681 has 20 divisors (see below), whose sum is σ = 5965659999684. Its totient is φ = 2610157500000.

The previous prime is 3954388620647. The next prime is 3954388620731. The reversal of 3954388620681 is 1860268834593.

It is a happy number.

3954388620681 is a `hidden beast` number, since 3 + 9 + 543 + 8 + 8 + 6 + 2 + 0 + 6 + 81 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3858313419081 + 96075201600 = 1964259^2 + 309960^2 .

It is not a de Polignac number, because 3954388620681 - 2¹⁷ = 3954388489609 is a prime.

It is a super-2 number, since 2×3954388620681² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3954388600681) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 241673070 + ... + 241689431.

Almost surely, 2^{3954388620681} is an apocalyptic number.

It is an amenable number.

3954388620681 is a deficient number, since it is larger than the sum of its proper divisors (2011271379003).

3954388620681 is a wasteful number, since it uses less digits than its factorization.

3954388620681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483362614 (or 483362605 counting only the distinct ones).

The product of its (nonzero) digits is 59719680, while the sum is 63.

The spelling of 3954388620681 in words is "three trillion, nine hundred fifty-four billion, three hundred eighty-eight million, six hundred twenty thousand, six hundred eighty-one".