3961596621376 has 21 divisors (see below), whose sum is σ = 7861324892889. Its totient is φ = 1980790349184.

The previous prime is 3961596621371. The next prime is 3961596621397. The reversal of 3961596621376 is 6731266951693.

It is a happy number.

The square root of 3961596621376 is 1990376.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3664161640000 + 297434981376 = 1914200^2 + 545376^2 .

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3961596621371) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 15798610 + ... + 16047406.

Almost surely, 2^{3961596621376} is an apocalyptic number.

3961596621376 is the 1990376-th square number.

It is an amenable number.

3961596621376 is a deficient number, since it is larger than the sum of its proper divisors (3899728271513).

3961596621376 is an frugal number, since it uses more digits than its factorization.

3961596621376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497606 (or 248799 counting only the distinct ones).

The product of its digits is 66134880, while the sum is 64.

Multiplying 3961596621376 by its sum of digits (64), we get a square (253542183768064 = 15923008²).

3961596621376 divided by its sum of digits (64) gives a square (61899947209 = 248797²).

The spelling of 3961596621376 in words is "three trillion, nine hundred sixty-one billion, five hundred ninety-six million, six hundred twenty-one thousand, three hundred seventy-six".