1221611010 has 32 divisors (see below), whose sum is σ = 2979934272. Its totient is φ = 320422080.

The previous prime is 1221611009. The next prime is 1221611033. The reversal of 1221611010 is 101161221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 331944 + ... + 335603.

It is an arithmetic number, because the mean of its divisors is an integer number (93122946).

Almost surely, 2^1221611010 is an apocalyptic number.

1221611010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221611010 is an abundant number, since it is smaller than the sum of its proper divisors (1758323262).

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

1221611010 is a wasteful number, since it uses less digits than its factorization.

1221611010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667618.

The product of its (nonzero) digits is 24, while the sum is 15.

The square root of 1221611010 is about 34951.5523260413. The cubic root of 1221611010 is about 1068.9998544461. Note that the first 3 decimals are identical.

Adding to 1221611010 its reverse (101161221), we get a palindrome (1322772231).

The spelling of 1221611010 in words is "one billion, two hundred twenty-one million, six hundred eleven thousand, ten".