721970019 has 24 divisors (see below), whose sum is σ = 1058616000. Its totient is φ = 474065280.

The previous prime is 721970009. The next prime is 721970027. The reversal of 721970019 is 910079127.

It is not a de Polignac number, because 721970019 - 2⁴ = 721970003 is a prime.

It is a super-2 number, since 2×721970019² = 1042481416669720722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (721970009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 369457 + ... + 371405.

It is an arithmetic number, because the mean of its divisors is an integer number (44109000).

Almost surely, 2^721970019 is an apocalyptic number.

721970019 is a gapful number since it is divisible by the number (79) formed by its first and last digit.

721970019 is a deficient number, since it is larger than the sum of its proper divisors (336645981).

721970019 is a wasteful number, since it uses less digits than its factorization.

721970019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2555 (or 2552 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 36.

The square root of 721970019 is about 26869.4997906548. The cubic root of 721970019 is about 897.0976541967.

The spelling of 721970019 in words is "seven hundred twenty-one million, nine hundred seventy thousand, nineteen".