221082637428 has 36 divisors (see below), whose sum is σ = 558926817540. Its totient is φ = 73683789696.

The previous prime is 221082637427. The next prime is 221082637469. The reversal of 221082637428 is 824736280122.

221082637428 is a `hidden beast` number, since 2 + 2 + 1 + 0 + 8 + 2 + 637 + 4 + 2 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 132720318864 + 88362318564 = 364308^2 + 297258^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221082637427) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 174075 + ... + 687362.

Almost surely, 2^221082637428 is an apocalyptic number.

It is an amenable number.

221082637428 is an abundant number, since it is smaller than the sum of its proper divisors (337844180112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221082637428 is a wasteful number, since it uses less digits than its factorization.

221082637428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868576 (or 868571 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The spelling of 221082637428 in words is "two hundred twenty-one billion, eighty-two million, six hundred thirty-seven thousand, four hundred twenty-eight".