1078423721 has 2 divisors, whose sum is σ = 1078423722. Its totient is φ = 1078423720.

The previous prime is 1078423693. The next prime is 1078423727. The reversal of 1078423721 is 1273248701.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1049047321 + 29376400 = 32389^2 + 5420^2 .

It is an emirp because it is prime and its reverse (1273248701) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1078423721 is a prime.

It is not a weakly prime, because it can be changed into another prime (1078423727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 539211860 + 539211861.

It is an arithmetic number, because the mean of its divisors is an integer number (539211861).

Almost surely, 2^1078423721 is an apocalyptic number.

It is an amenable number.

1078423721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1078423721 is an equidigital number, since it uses as much as digits as its factorization.

1078423721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 1078423721 is about 32839.3623720072. The cubic root of 1078423721 is about 1025.4861769751.

The spelling of 1078423721 in words is "one billion, seventy-eight million, four hundred twenty-three thousand, seven hundred twenty-one".