1019728723 has 4 divisors (see below), whose sum is σ = 1098169408. Its totient is φ = 941288040.

The previous prime is 1019728709. The next prime is 1019728729. The reversal of 1019728723 is 3278279101.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1019728723 - 2²⁵ = 986174291 is a prime.

It is a super-2 number, since 2×1019728723² = 2079693337022421458, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1019728729) 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, 39220323 + ... + 39220348.

It is an arithmetic number, because the mean of its divisors is an integer number (274542352).

Almost surely, 2^1019728723 is an apocalyptic number.

1019728723 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1019728723 is a deficient number, since it is larger than the sum of its proper divisors (78440685).

1019728723 is an equidigital number, since it uses as much as digits as its factorization.

1019728723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78440684.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 1019728723 is about 31933.1915567486. The cubic root of 1019728723 is about 1006.5334619127.

The spelling of 1019728723 in words is "one billion, nineteen million, seven hundred twenty-eight thousand, seven hundred twenty-three".