1004688721 has 2 divisors, whose sum is σ = 1004688722. Its totient is φ = 1004688720.

The previous prime is 1004688709. The next prime is 1004688733. The reversal of 1004688721 is 1278864001.

It is a balanced prime because it is at equal distance from previous prime (1004688709) and next prime (1004688733).

It can be written as a sum of positive squares in only one way, i.e., 862244496 + 142444225 = 29364^2 + 11935^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1004688721 is a prime.

It is a super-2 number, since 2×1004688721² = 2018798852209231682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1004688761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502344360 + 502344361.

It is an arithmetic number, because the mean of its divisors is an integer number (502344361).

Almost surely, 2^1004688721 is an apocalyptic number.

It is an amenable number.

1004688721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1004688721 is an equidigital number, since it uses as much as digits as its factorization.

1004688721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 1004688721 is about 31696.8250933749. The cubic root of 1004688721 is about 1001.5604706647.

It can be divided in two parts, 1004 and 688721, that added together give a triangular number (689725 = T₁₁₇₄).

The spelling of 1004688721 in words is "one billion, four million, six hundred eighty-eight thousand, seven hundred twenty-one".