3948545921 has 4 divisors (see below), whose sum is σ = 4013276244. Its totient is φ = 3883815600.

The previous prime is 3948545903. The next prime is 3948545947. The reversal of 3948545921 is 1295458493.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1240800625 + 2707745296 = 35225^2 + 52036^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3948545921 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3948545921.

It is not an unprimeable number, because it can be changed into a prime (3948545521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32365070 + ... + 32365191.

It is an arithmetic number, because the mean of its divisors is an integer number (1003319061).

Almost surely, 2^3948545921 is an apocalyptic number.

It is an amenable number.

3948545921 is a deficient number, since it is larger than the sum of its proper divisors (64730323).

3948545921 is an equidigital number, since it uses as much as digits as its factorization.

3948545921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64730322.

The product of its digits is 1555200, while the sum is 50.

The square root of 3948545921 is about 62837.4563536749. The cubic root of 3948545921 is about 1580.5651347235.

The spelling of 3948545921 in words is "three billion, nine hundred forty-eight million, five hundred forty-five thousand, nine hundred twenty-one".