37699721 has 4 divisors (see below), whose sum is σ = 38045700. Its totient is φ = 37353744.

The previous prime is 37699709. The next prime is 37699723. The reversal of 37699721 is 12799673.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12799673 = 19 ⋅673667.

It can be written as a sum of positive squares in 2 ways, for example, as 26214400 + 11485321 = 5120^2 + 3389^2 .

It is a cyclic number.

It is not a de Polignac number, because 37699721 - 2¹⁴ = 37683337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (37699723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172826 + ... + 173043.

It is an arithmetic number, because the mean of its divisors is an integer number (9511425).

Almost surely, 2^37699721 is an apocalyptic number.

It is an amenable number.

37699721 is a deficient number, since it is larger than the sum of its proper divisors (345979).

37699721 is a wasteful number, since it uses less digits than its factorization.

37699721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345978.

The product of its digits is 142884, while the sum is 44.

The square root of 37699721 is about 6140.0098534123. The cubic root of 37699721 is about 335.3096446457.

The spelling of 37699721 in words is "thirty-seven million, six hundred ninety-nine thousand, seven hundred twenty-one".