425661521 has 4 divisors (see below), whose sum is σ = 450700452. Its totient is φ = 400622592.

The previous prime is 425661517. The next prime is 425661539. The reversal of 425661521 is 125166524.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 120670225 + 304991296 = 10985^2 + 17464^2 .

It is a cyclic number.

It is not a de Polignac number, because 425661521 - 2² = 425661517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (425661581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12519440 + ... + 12519473.

It is an arithmetic number, because the mean of its divisors is an integer number (112675113).

Almost surely, 2^425661521 is an apocalyptic number.

It is an amenable number.

425661521 is a deficient number, since it is larger than the sum of its proper divisors (25038931).

425661521 is a wasteful number, since it uses less digits than its factorization.

425661521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25038930.

The product of its digits is 14400, while the sum is 32.

The square root of 425661521 is about 20631.5661305680. The cubic root of 425661521 is about 752.2371843360.

The spelling of 425661521 in words is "four hundred twenty-five million, six hundred sixty-one thousand, five hundred twenty-one".