221970431 has 4 divisors (see below), whose sum is σ = 222028200. Its totient is φ = 221912664.

The previous prime is 221970403. The next prime is 221970439. The reversal of 221970431 is 134079122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221970431 is a prime.

It is a super-2 number, since 2×221970431² = 98541744476651522, 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 = 221970394 and 221970403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221970439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22676 + ... + 30953.

It is an arithmetic number, because the mean of its divisors is an integer number (55507050).

Almost surely, 2^221970431 is an apocalyptic number.

221970431 is a deficient number, since it is larger than the sum of its proper divisors (57769).

221970431 is an equidigital number, since it uses as much as digits as its factorization.

221970431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57768.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 221970431 is about 14898.6721220383. The cubic root of 221970431 is about 605.4780103130.

The spelling of 221970431 in words is "two hundred twenty-one million, nine hundred seventy thousand, four hundred thirty-one".