1056721401 has 12 divisors (see below), whose sum is σ = 1579009380. Its totient is φ = 680188320.

The previous prime is 1056721381. The next prime is 1056721409. The reversal of 1056721401 is 1041276501.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 478559376 + 578162025 = 21876^2 + 24045^2 .

It is not a de Polignac number, because 1056721401 - 2¹³ = 1056713209 is a prime.

It is a super-2 number, since 2×1056721401² = 2233320238662805602, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1056721409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2024110 + ... + 2024631.

It is an arithmetic number, because the mean of its divisors is an integer number (131584115).

Almost surely, 2^1056721401 is an apocalyptic number.

It is an amenable number.

1056721401 is a deficient number, since it is larger than the sum of its proper divisors (522287979).

1056721401 is a wasteful number, since it uses less digits than its factorization.

1056721401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4048776 (or 4048773 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 1056721401 is about 32507.2515140853. The cubic root of 1056721401 is about 1018.5605098228.

Adding to 1056721401 its reverse (1041276501), we get a palindrome (2097997902).

Subtracting from 1056721401 its reverse (1041276501), we obtain a square (15444900 = 3930²).

The spelling of 1056721401 in words is "one billion, fifty-six million, seven hundred twenty-one thousand, four hundred one".