43421320997 has 2 divisors, whose sum is σ = 43421320998. Its totient is φ = 43421320996.

The previous prime is 43421320949. The next prime is 43421321003. The reversal of 43421320997 is 79902312434.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35459149636 + 7962171361 = 188306^2 + 89231^2 .

It is a cyclic number.

It is not a de Polignac number, because 43421320997 - 2²⁸ = 43152885541 is a prime.

It is a super-2 number, since 2×43421320997² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43421320907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21710660498 + 21710660499.

It is an arithmetic number, because the mean of its divisors is an integer number (21710660499).

Almost surely, 2^43421320997 is an apocalyptic number.

It is an amenable number.

43421320997 is a deficient number, since it is larger than the sum of its proper divisors (1).

43421320997 is an equidigital number, since it uses as much as digits as its factorization.

43421320997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 326592, while the sum is 44.

The spelling of 43421320997 in words is "forty-three billion, four hundred twenty-one million, three hundred twenty thousand, nine hundred ninety-seven".