101221989 has 32 divisors (see below), whose sum is σ = 152893440. Its totient is φ = 59030400.

The previous prime is 101221979. The next prime is 101222021. The reversal of 101221989 is 989122101.

It is not a de Polignac number, because 101221989 - 2⁸ = 101221733 is a prime.

It is a super-2 number, since 2×101221989² = 20491782114232242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101221909) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 106414 + ... + 107360.

It is an arithmetic number, because the mean of its divisors is an integer number (4777920).

Almost surely, 2^101221989 is an apocalyptic number.

It is an amenable number.

101221989 is a deficient number, since it is larger than the sum of its proper divisors (51671451).

101221989 is a wasteful number, since it uses less digits than its factorization.

101221989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1081.

The product of its (nonzero) digits is 2592, while the sum is 33.

The square root of 101221989 is about 10060.9139246889. The cubic root of 101221989 is about 466.0418908475.

The spelling of 101221989 in words is "one hundred one million, two hundred twenty-one thousand, nine hundred eighty-nine".