721654477 has 4 divisors (see below), whose sum is σ = 722905756. Its totient is φ = 720403200.

The previous prime is 721654469. The next prime is 721654481. The reversal of 721654477 is 774456127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 774456127 = 227 ⋅3411701.

It can be written as a sum of positive squares in 2 ways, for example, as 584624041 + 137030436 = 24179^2 + 11706^2 .

It is a cyclic number.

It is not a de Polignac number, because 721654477 - 2³ = 721654469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721654457) 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, 624774 + ... + 625927.

It is an arithmetic number, because the mean of its divisors is an integer number (180726439).

Almost surely, 2^721654477 is an apocalyptic number.

It is an amenable number.

721654477 is a deficient number, since it is larger than the sum of its proper divisors (1251279).

721654477 is a wasteful number, since it uses less digits than its factorization.

721654477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1251278.

The product of its digits is 329280, while the sum is 43.

The square root of 721654477 is about 26863.6273983988. The cubic root of 721654477 is about 896.9669409030.

The spelling of 721654477 in words is "seven hundred twenty-one million, six hundred fifty-four thousand, four hundred seventy-seven".