1012155221 has 12 divisors (see below), whose sum is σ = 1284442560. Its totient is φ = 788691960.

The previous prime is 1012155217. The next prime is 1012155247. The reversal of 1012155221 is 1225512101.

It is not a de Polignac number, because 1012155221 - 2² = 1012155217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1012155193 and 1012155202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1012155121) 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, 938381 + ... + 939458.

It is an arithmetic number, because the mean of its divisors is an integer number (107036880).

Almost surely, 2^1012155221 is an apocalyptic number.

1012155221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1012155221 is a deficient number, since it is larger than the sum of its proper divisors (272287339).

1012155221 is a wasteful number, since it uses less digits than its factorization.

1012155221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1877864 (or 1877857 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 1012155221 is about 31814.3870127966. The cubic root of 1012155221 is about 1004.0354337029.

Adding to 1012155221 its reverse (1225512101), we get a palindrome (2237667322).

The spelling of 1012155221 in words is "one billion, twelve million, one hundred fifty-five thousand, two hundred twenty-one".