721553742 has 48 divisors (see below), whose sum is σ = 1924147680. Its totient is φ = 190299456.

The previous prime is 721553719. The next prime is 721553771. The reversal of 721553742 is 247355127.

721553742 is a `hidden beast` number, since 72 + 15 + 537 + 42 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 721553697 and 721553706.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 218617 + ... + 221892.

It is an arithmetic number, because the mean of its divisors is an integer number (40086410).

Almost surely, 2^721553742 is an apocalyptic number.

721553742 is an abundant number, since it is smaller than the sum of its proper divisors (1202593938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721553742 is a wasteful number, since it uses less digits than its factorization.

721553742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440537 (or 440534 counting only the distinct ones).

The product of its digits is 58800, while the sum is 36.

The square root of 721553742 is about 26861.7524000204. The cubic root of 721553742 is about 896.9252033992.

The spelling of 721553742 in words is "seven hundred twenty-one million, five hundred fifty-three thousand, seven hundred forty-two".