221990156 has 6 divisors (see below), whose sum is σ = 388482780. Its totient is φ = 110995076.

The previous prime is 221990137. The next prime is 221990159. The reversal of 221990156 is 651099122.

221990156 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (221990159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27748766 + ... + 27748773.

It is an arithmetic number, because the mean of its divisors is an integer number (64747130).

Almost surely, 2^221990156 is an apocalyptic number.

It is an amenable number.

221990156 is a deficient number, since it is larger than the sum of its proper divisors (166492624).

221990156 is a wasteful number, since it uses less digits than its factorization.

221990156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55497543 (or 55497541 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 221990156 is about 14899.3340790788. The cubic root of 221990156 is about 605.4959446837.

The spelling of 221990156 in words is "two hundred twenty-one million, nine hundred ninety thousand, one hundred fifty-six".