37999900021 has 4 divisors (see below), whose sum is σ = 38277271692. Its totient is φ = 37722528352.

The previous prime is 37999900009. The next prime is 37999900033. The reversal of 37999900021 is 12000999973.

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

It is an interprime number because it is at equal distance from previous prime (37999900009) and next prime (37999900033).

It can be written as a sum of positive squares in 2 ways, for example, as 22926199396 + 15073700625 = 151414^2 + 122775^2 .

It is a cyclic number.

It is not a de Polignac number, because 37999900021 - 2¹³ = 37999891829 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (37999900721) 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, 138685630 + ... + 138685903.

It is an arithmetic number, because the mean of its divisors is an integer number (9569317923).

Almost surely, 2^37999900021 is an apocalyptic number.

It is an amenable number.

37999900021 is a deficient number, since it is larger than the sum of its proper divisors (277371671).

37999900021 is a wasteful number, since it uses less digits than its factorization.

37999900021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277371670.

The product of its (nonzero) digits is 275562, while the sum is 49.

The spelling of 37999900021 in words is "thirty-seven billion, nine hundred ninety-nine million, nine hundred thousand, twenty-one".