1221261010 has 16 divisors (see below), whose sum is σ = 2209320000. Its totient is φ = 486048816.

The previous prime is 1221261007. The next prime is 1221261023. The reversal of 1221261010 is 101621221.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 304860 + ... + 308839.

It is an arithmetic number, because the mean of its divisors is an integer number (138082500).

Almost surely, 2^1221261010 is an apocalyptic number.

1221261010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221261010 is a deficient number, since it is larger than the sum of its proper divisors (988058990).

1221261010 is a wasteful number, since it uses less digits than its factorization.

1221261010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613905.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 1221261010 is about 34946.5450366699. The cubic root of 1221261010 is about 1068.8977527449.

Adding to 1221261010 its reverse (101621221), we get a palindrome (1322882231).

The spelling of 1221261010 in words is "one billion, two hundred twenty-one million, two hundred sixty-one thousand, ten".