447213721 has 2 divisors, whose sum is σ = 447213722. Its totient is φ = 447213720.

The previous prime is 447213673. The next prime is 447213733. The reversal of 447213721 is 127312744.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250905600 + 196308121 = 15840^2 + 14011^2 .

It is a cyclic number.

It is not a de Polignac number, because 447213721 - 2²⁵ = 413659289 is a prime.

It is a super-2 number, since 2×447213721² = 400000224501331682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (447213761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 223606860 + 223606861.

It is an arithmetic number, because the mean of its divisors is an integer number (223606861).

Almost surely, 2^447213721 is an apocalyptic number.

It is an amenable number.

447213721 is a deficient number, since it is larger than the sum of its proper divisors (1).

447213721 is an equidigital number, since it uses as much as digits as its factorization.

447213721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 31.

The square root of 447213721 is about 21147.4282360764. The cubic root of 447213721 is about 764.7245628657.

The spelling of 447213721 in words is "four hundred forty-seven million, two hundred thirteen thousand, seven hundred twenty-one".