1949730721 has 4 divisors (see below), whose sum is σ = 1950112944. Its totient is φ = 1949348500.

The previous prime is 1949730683. The next prime is 1949730763. The reversal of 1949730721 is 1270379491.

It is a happy number.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1949730721 is a prime.

It is a super-2 number, since 2×1949730721² = 7602899768822359682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1949730791) 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, 183355 + ... + 193696.

It is an arithmetic number, because the mean of its divisors is an integer number (487528236).

Almost surely, 2^1949730721 is an apocalyptic number.

It is an amenable number.

1949730721 is a deficient number, since it is larger than the sum of its proper divisors (382223).

1949730721 is an equidigital number, since it uses as much as digits as its factorization.

1949730721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382222.

The product of its (nonzero) digits is 95256, while the sum is 43.

The square root of 1949730721 is about 44155.7552420973. The cubic root of 1949730721 is about 1249.2754672697.

The spelling of 1949730721 in words is "one billion, nine hundred forty-nine million, seven hundred thirty thousand, seven hundred twenty-one".