1021021221 has 64 divisors (see below), whose sum is σ = 1649756160. Its totient is φ = 554400000.

The previous prime is 1021021219. The next prime is 1021021223. The reversal of 1021021221 is 1221201201.

It is an interprime number because it is at equal distance from previous prime (1021021219) and next prime (1021021223).

It is not a de Polignac number, because 1021021221 - 2¹ = 1021021219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021021197 and 1021021206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021021223) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1456171 + ... + 1456871.

It is an arithmetic number, because the mean of its divisors is an integer number (25777440).

Almost surely, 2^1021021221 is an apocalyptic number.

1021021221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1021021221 is a deficient number, since it is larger than the sum of its proper divisors (628734939).

1021021221 is a wasteful number, since it uses less digits than its factorization.

1021021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1021021221 is about 31953.4226805205. The cubic root of 1021021221 is about 1006.9585400729.

Adding to 1021021221 its reverse (1221201201), we get a palindrome (2242222422).

The spelling of 1021021221 in words is "one billion, twenty-one million, twenty-one thousand, two hundred twenty-one".