425667661 has 4 divisors (see below), whose sum is σ = 426556800. Its totient is φ = 424778524.

The previous prime is 425667611. The next prime is 425667667. The reversal of 425667661 is 166766524.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 425667661 - 2¹¹ = 425665613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (425667667) 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, 443851 + ... + 444808.

It is an arithmetic number, because the mean of its divisors is an integer number (106639200).

Almost surely, 2^425667661 is an apocalyptic number.

It is an amenable number.

425667661 is a deficient number, since it is larger than the sum of its proper divisors (889139).

425667661 is an equidigital number, since it uses as much as digits as its factorization.

425667661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889138.

The product of its digits is 362880, while the sum is 43.

The square root of 425667661 is about 20631.7149311442. The cubic root of 425667661 is about 752.2408012271.

It can be divided in two parts, 4256 and 67661, that added together give a palindrome (71917).

The spelling of 425667661 in words is "four hundred twenty-five million, six hundred sixty-seven thousand, six hundred sixty-one".