39721043 has 2 divisors, whose sum is σ = 39721044. Its totient is φ = 39721042.

The previous prime is 39720971. The next prime is 39721049. The reversal of 39721043 is 34012793.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 39721043 - 2⁸ = 39720787 is a prime.

It is a super-2 number, since 2×39721043² = 3155522514015698, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 39720997 and 39721015.

It is not a weakly prime, because it can be changed into another prime (39721049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19860521 + 19860522.

It is an arithmetic number, because the mean of its divisors is an integer number (19860522).

Almost surely, 2^39721043 is an apocalyptic number.

39721043 is a deficient number, since it is larger than the sum of its proper divisors (1).

39721043 is an equidigital number, since it uses as much as digits as its factorization.

39721043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 39721043 is about 6302.4632486037. The cubic root of 39721043 is about 341.1983177466.

The spelling of 39721043 in words is "thirty-nine million, seven hundred twenty-one thousand, forty-three".