4003978729 has 3 divisors (see below), whose sum is σ = 4004042007. Its totient is φ = 4003915452.

The previous prime is 4003978709. The next prime is 4003978733. The reversal of 4003978729 is 9278793004.

The square root of 4003978729 is 63277.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 66667225 + 3937311504 = 8165^2 + 62748^2 .

It is not a de Polignac number, because 4003978729 - 2¹¹ = 4003976681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4003978709) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 31639 + ... + 94915.

It is an arithmetic number, because the mean of its divisors is an integer number (1334680669).

Almost surely, 2^4003978729 is an apocalyptic number.

4003978729 is the 63277-th square number.

4003978729 is the 31639-th centered octagonal number.

It is an amenable number.

4003978729 is a deficient number, since it is larger than the sum of its proper divisors (63278).

4003978729 is an frugal number, since it uses more digits than its factorization.

4003978729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126554 (or 63277 counting only the distinct ones).

The product of its (nonzero) digits is 762048, while the sum is 49.

The cubic root of 4003978729 is about 1587.9271974409.

Multiplying 4003978729 by its sum of digits (49), we get a square (196194957721 = 442939²).

The spelling of 4003978729 in words is "four billion, three million, nine hundred seventy-eight thousand, seven hundred twenty-nine".