21040001425 has 6 divisors (see below), whose sum is σ = 26089601798. Its totient is φ = 16832001120.

The previous prime is 21040001399. The next prime is 21040001441. The reversal of 21040001425 is 52410004012.

It can be written as a sum of positive squares in 3 ways, for example, as 3486666304 + 17553335121 = 59048^2 + 132489^2 .

It is not a de Polignac number, because 21040001425 - 2¹¹ = 21039999377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 420800004 + ... + 420800053.

Almost surely, 2^21040001425 is an apocalyptic number.

21040001425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21040001425 is a deficient number, since it is larger than the sum of its proper divisors (5049600373).

21040001425 is an equidigital number, since it uses as much as digits as its factorization.

21040001425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841600067 (or 841600062 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

Adding to 21040001425 its reverse (52410004012), we get a palindrome (73450005437).

The spelling of 21040001425 in words is "twenty-one billion, forty million, one thousand, four hundred twenty-five".