37220721 has 4 divisors (see below), whose sum is σ = 49627632. Its totient is φ = 24813812.

The previous prime is 37220653. The next prime is 37220737. The reversal of 37220721 is 12702273.

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: 12702273 = 3 ⋅4234091.

It is a cyclic number.

It is not a de Polignac number, because 37220721 - 2⁷ = 37220593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 37220691 and 37220700.

It is not an unprimeable number, because it can be changed into a prime (37220741) 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, 6203451 + ... + 6203456.

It is an arithmetic number, because the mean of its divisors is an integer number (12406908).

Almost surely, 2^37220721 is an apocalyptic number.

It is an amenable number.

37220721 is a deficient number, since it is larger than the sum of its proper divisors (12406911).

37220721 is a wasteful number, since it uses less digits than its factorization.

37220721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12406910.

The product of its (nonzero) digits is 1176, while the sum is 24.

The square root of 37220721 is about 6100.8787072028. The cubic root of 37220721 is about 333.8834767494.

Adding to 37220721 its reverse (12702273), we get a palindrome (49922994).

The spelling of 37220721 in words is "thirty-seven million, two hundred twenty thousand, seven hundred twenty-one".