721644467 has 4 divisors (see below), whose sum is σ = 721703136. Its totient is φ = 721585800.

The previous prime is 721644409. The next prime is 721644479. The reversal of 721644467 is 764446127.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 764446127 = 8221 ⋅92987.

It is a cyclic number.

It is not a de Polignac number, because 721644467 - 2¹⁰ = 721643443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721644367) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3008 + ... + 38109.

It is an arithmetic number, because the mean of its divisors is an integer number (180425784).

Almost surely, 2^721644467 is an apocalyptic number.

721644467 is a deficient number, since it is larger than the sum of its proper divisors (58669).

721644467 is a wasteful number, since it uses less digits than its factorization.

721644467 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58668.

The product of its digits is 225792, while the sum is 41.

The square root of 721644467 is about 26863.4410863538. The cubic root of 721644467 is about 896.9627936364.

The spelling of 721644467 in words is "seven hundred twenty-one million, six hundred forty-four thousand, four hundred sixty-seven".