39900220021 has 4 divisors (see below), whose sum is σ = 39922013344. Its totient is φ = 39878426700.

The previous prime is 39900220013. The next prime is 39900220027. The reversal of 39900220021 is 12002200993.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12002200993 = 499 ⋅24052507.

It is a cyclic number.

It is not a de Polignac number, because 39900220021 - 2³ = 39900220013 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 (39900220027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10893915 + ... + 10897576.

It is an arithmetic number, because the mean of its divisors is an integer number (9980503336).

Almost surely, 2^39900220021 is an apocalyptic number.

It is an amenable number.

39900220021 is a deficient number, since it is larger than the sum of its proper divisors (21793323).

39900220021 is a wasteful number, since it uses less digits than its factorization.

39900220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21793322.

The product of its (nonzero) digits is 1944, while the sum is 28.

The spelling of 39900220021 in words is "thirty-nine billion, nine hundred million, two hundred twenty thousand, twenty-one".