221708542 has 24 divisors (see below), whose sum is σ = 366837408. Its totient is φ = 100420320.

The previous prime is 221708537. The next prime is 221708581. The reversal of 221708542 is 245807122.

It is a happy number.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 74283 + ... + 77209.

It is an arithmetic number, because the mean of its divisors is an integer number (15284892).

Almost surely, 2^221708542 is an apocalyptic number.

221708542 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

221708542 is a deficient number, since it is larger than the sum of its proper divisors (145128866).

221708542 is a wasteful number, since it uses less digits than its factorization.

221708542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3264 (or 3253 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 221708542 is about 14889.8805233622. The cubic root of 221708542 is about 605.2397947508.

The spelling of 221708542 in words is "two hundred twenty-one million, seven hundred eight thousand, five hundred forty-two".