221550554 has 4 divisors (see below), whose sum is σ = 332325834. Its totient is φ = 110775276.

The previous prime is 221550551. The next prime is 221550557. The reversal of 221550554 is 455055122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 455055122 = 2 ⋅227527561.

It is an interprime number because it is at equal distance from previous prime (221550551) and next prime (221550557).

It can be written as a sum of positive squares in only one way, i.e., 188430529 + 33120025 = 13727^2 + 5755^2 .

It is not an unprimeable number, because it can be changed into a prime (221550551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55387637 + ... + 55387640.

Almost surely, 2^221550554 is an apocalyptic number.

221550554 is a deficient number, since it is larger than the sum of its proper divisors (110775280).

221550554 is a wasteful number, since it uses less digits than its factorization.

221550554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110775279.

The product of its (nonzero) digits is 10000, while the sum is 29.

The square root of 221550554 is about 14884.5743640858. The cubic root of 221550554 is about 605.0959973344.

The spelling of 221550554 in words is "two hundred twenty-one million, five hundred fifty thousand, five hundred fifty-four".