1401172721 has 8 divisors (see below), whose sum is σ = 1549738344. Its totient is φ = 1258433280.

The previous prime is 1401172687. The next prime is 1401172741. The reversal of 1401172721 is 1272711041.

It can be written as a sum of positive squares in 4 ways, for example, as 12567025 + 1388605696 = 3545^2 + 37264^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-1401172721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1401172741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1456040 + ... + 1457001.

It is an arithmetic number, because the mean of its divisors is an integer number (193717293).

Almost surely, 2^1401172721 is an apocalyptic number.

It is an amenable number.

1401172721 is a deficient number, since it is larger than the sum of its proper divisors (148565623).

1401172721 is a wasteful number, since it uses less digits than its factorization.

1401172721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2913091.

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 1401172721 is about 37432.2417308929. The cubic root of 1401172721 is about 1119.0012144325.

Adding to 1401172721 its reverse (1272711041), we get a palindrome (2673883762).

The spelling of 1401172721 in words is "one billion, four hundred one million, one hundred seventy-two thousand, seven hundred twenty-one".