5406939721 has 2 divisors, whose sum is σ = 5406939722. Its totient is φ = 5406939720.

The previous prime is 5406939689. The next prime is 5406939749. The reversal of 5406939721 is 1279396045.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2781402121 + 2625537600 = 52739^2 + 51240^2 .

It is a cyclic number.

It is not a de Polignac number, because 5406939721 - 2⁵ = 5406939689 is a prime.

It is not a weakly prime, because it can be changed into another prime (5406939761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2703469860 + 2703469861.

It is an arithmetic number, because the mean of its divisors is an integer number (2703469861).

Almost surely, 2^5406939721 is an apocalyptic number.

It is an amenable number.

5406939721 is a deficient number, since it is larger than the sum of its proper divisors (1).

5406939721 is an equidigital number, since it uses as much as digits as its factorization.

5406939721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 408240, while the sum is 46.

The square root of 5406939721 is about 73531.8959431892. The cubic root of 5406939721 is about 1755.1618718506.

The spelling of 5406939721 in words is "five billion, four hundred six million, nine hundred thirty-nine thousand, seven hundred twenty-one".