221978037 has 8 divisors (see below), whose sum is σ = 308839104. Its totient is φ = 141551168.

The previous prime is 221978033. The next prime is 221978041. The reversal of 221978037 is 730879122.

It is an interprime number because it is at equal distance from previous prime (221978033) and next prime (221978041).

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 221978037 - 2² = 221978033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221977986 and 221978004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221978033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1608468 + ... + 1608605.

It is an arithmetic number, because the mean of its divisors is an integer number (38604888).

Almost surely, 2^221978037 is an apocalyptic number.

It is an amenable number.

221978037 is a deficient number, since it is larger than the sum of its proper divisors (86861067).

221978037 is a wasteful number, since it uses less digits than its factorization.

221978037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3217099.

The product of its (nonzero) digits is 42336, while the sum is 39.

The square root of 221978037 is about 14898.9273774994. The cubic root of 221978037 is about 605.4849259686.

The spelling of 221978037 in words is "two hundred twenty-one million, nine hundred seventy-eight thousand, thirty-seven".