721666670037 has 4 divisors (see below), whose sum is σ = 962222226720. Its totient is φ = 481111113356.

The previous prime is 721666670029. The next prime is 721666670051. The reversal of 721666670037 is 730076666127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 730076666127 = 3 ⋅243358888709.

It is a cyclic number.

It is not a de Polignac number, because 721666670037 - 2³ = 721666670029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721666660037) 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, 120277778337 + ... + 120277778342.

It is an arithmetic number, because the mean of its divisors is an integer number (240555556680).

Almost surely, 2^721666670037 is an apocalyptic number.

It is an amenable number.

721666670037 is a deficient number, since it is larger than the sum of its proper divisors (240555556683).

721666670037 is a wasteful number, since it uses less digits than its factorization.

721666670037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240555556682.

The product of its (nonzero) digits is 2667168, while the sum is 51.

The spelling of 721666670037 in words is "seven hundred twenty-one billion, six hundred sixty-six million, six hundred seventy thousand, thirty-seven".