3949967732821 has 4 divisors (see below), whose sum is σ = 4309055708544. Its totient is φ = 3590879757100.

The previous prime is 3949967732813. The next prime is 3949967732833. The reversal of 3949967732821 is 1282377699493.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3949967732821 - 2³ = 3949967732813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3949967732861) 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, 179543987845 + ... + 179543987866.

It is an arithmetic number, because the mean of its divisors is an integer number (1077263927136).

Almost surely, 2^{3949967732821} is an apocalyptic number.

It is an amenable number.

3949967732821 is a deficient number, since it is larger than the sum of its proper divisors (359087975723).

3949967732821 is a wasteful number, since it uses less digits than its factorization.

3949967732821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359087975722.

The product of its digits is 246903552, while the sum is 70.

The spelling of 3949967732821 in words is "three trillion, nine hundred forty-nine billion, nine hundred sixty-seven million, seven hundred thirty-two thousand, eight hundred twenty-one".