3920197821 has 16 divisors (see below), whose sum is σ = 5376674688. Its totient is φ = 2539123200.

The previous prime is 3920197793. The next prime is 3920197823. The reversal of 3920197821 is 1287910293.

It is not a de Polignac number, because 3920197821 - 2¹⁴ = 3920181437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3920197823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36481 + ... + 95766.

It is an arithmetic number, because the mean of its divisors is an integer number (336042168).

Almost surely, 2^3920197821 is an apocalyptic number.

It is an amenable number.

3920197821 is a deficient number, since it is larger than the sum of its proper divisors (1456476867).

3920197821 is a wasteful number, since it uses less digits than its factorization.

3920197821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132532.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 3920197821 is about 62611.4831400758. The cubic root of 3920197821 is about 1576.7735554466.

The spelling of 3920197821 in words is "three billion, nine hundred twenty million, one hundred ninety-seven thousand, eight hundred twenty-one".