221425531 has 8 divisors (see below), whose sum is σ = 231233184. Its totient is φ = 211632960.

The previous prime is 221425517. The next prime is 221425549. The reversal of 221425531 is 135524122.

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

It is a cyclic number.

It is not a de Polignac number, because 221425531 - 2⁷ = 221425403 is a prime.

It is a super-2 number, since 2×221425531² = 98058531557263922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221425496 and 221425505.

It is not an unprimeable number, because it can be changed into a prime (221425511) 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, 34711 + ... + 40591.

It is an arithmetic number, because the mean of its divisors is an integer number (28904148).

Almost surely, 2^221425531 is an apocalyptic number.

221425531 is a deficient number, since it is larger than the sum of its proper divisors (9807653).

221425531 is a wasteful number, since it uses less digits than its factorization.

221425531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7541.

The product of its digits is 2400, while the sum is 25.

The square root of 221425531 is about 14880.3740208370. The cubic root of 221425531 is about 604.9821555195.

Adding to 221425531 its reverse (135524122), we get a palindrome (356949653).

The spelling of 221425531 in words is "two hundred twenty-one million, four hundred twenty-five thousand, five hundred thirty-one".