1221001210 has 64 divisors (see below), whose sum is σ = 2671159680. Its totient is φ = 395700480.

The previous prime is 1221001189. The next prime is 1221001261. The reversal of 1221001210 is 121001221.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26749 + ... + 56191.

It is an arithmetic number, because the mean of its divisors is an integer number (41736870).

Almost surely, 2^1221001210 is an apocalyptic number.

1221001210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221001210 is an abundant number, since it is smaller than the sum of its proper divisors (1450158470).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221001210 is a wasteful number, since it uses less digits than its factorization.

1221001210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29503.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1221001210 is about 34942.8277333132. The cubic root of 1221001210 is about 1068.8219514957.

Adding to 1221001210 its reverse (121001221), we get a palindrome (1342002431).

The spelling of 1221001210 in words is "one billion, two hundred twenty-one million, one thousand, two hundred ten".