438078007721 has 2 divisors, whose sum is σ = 438078007722. Its totient is φ = 438078007720.

The previous prime is 438078007691. The next prime is 438078007739. The reversal of 438078007721 is 127700870834.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399164922025 + 38913085696 = 631795^2 + 197264^2 .

It is a cyclic number.

It is not a de Polignac number, because 438078007721 - 2³⁰ = 437004265897 is a prime.

It is a super-2 number, since 2×438078007721² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (438078007751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 219039003860 + 219039003861.

It is an arithmetic number, because the mean of its divisors is an integer number (219039003861).

Almost surely, 2^438078007721 is an apocalyptic number.

It is an amenable number.

438078007721 is a deficient number, since it is larger than the sum of its proper divisors (1).

438078007721 is an equidigital number, since it uses as much as digits as its factorization.

438078007721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 526848, while the sum is 47.

The spelling of 438078007721 in words is "four hundred thirty-eight billion, seventy-eight million, seven thousand, seven hundred twenty-one".