3956658659421 has 16 divisors (see below), whose sum is σ = 5705739539136. Its totient is φ = 2424416789376.

The previous prime is 3956658659389. The next prime is 3956658659537. The reversal of 3956658659421 is 1249568566593.

It is not a de Polignac number, because 3956658659421 - 2⁵ = 3956658659389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3956658659621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 217700755 + ... + 217718928.

It is an arithmetic number, because the mean of its divisors is an integer number (356608721196).

Almost surely, 2^{3956658659421} is an apocalyptic number.

It is an amenable number.

3956658659421 is a deficient number, since it is larger than the sum of its proper divisors (1749080879715).

3956658659421 is a wasteful number, since it uses less digits than its factorization.

3956658659421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435419932.

The product of its digits is 419904000, while the sum is 69.

The spelling of 3956658659421 in words is "three trillion, nine hundred fifty-six billion, six hundred fifty-eight million, six hundred fifty-nine thousand, four hundred twenty-one".