721748649 has 8 divisors (see below), whose sum is σ = 1012980640. Its totient is φ = 455841216.

The previous prime is 721748627. The next prime is 721748663. The reversal of 721748649 is 946847127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721748649 - 2⁸ = 721748393 is a prime.

It is a super-2 number, since 2×721748649² = 1041842224666650402, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721748598 and 721748607.

It is not an unprimeable number, because it can be changed into a prime (721748669) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 6331072 + ... + 6331185.

It is an arithmetic number, because the mean of its divisors is an integer number (126622580).

Almost surely, 2^721748649 is an apocalyptic number.

It is an amenable number.

721748649 is a deficient number, since it is larger than the sum of its proper divisors (291231991).

721748649 is a wasteful number, since it uses less digits than its factorization.

721748649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12662279.

The product of its digits is 677376, while the sum is 48.

The square root of 721748649 is about 26865.3801201472. The cubic root of 721748649 is about 897.0059556483.

The spelling of 721748649 in words is "seven hundred twenty-one million, seven hundred forty-eight thousand, six hundred forty-nine".