1221715710 has 160 divisors (see below), whose sum is σ = 3501701280. Its totient is φ = 305627904.

The previous prime is 1221715657. The next prime is 1221715711. The reversal of 1221715710 is 175171221.

1221715710 is a `hidden beast` number, since 1 + 2 + 21 + 71 + 571 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221715711) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3979377 + ... + 3979683.

It is an arithmetic number, because the mean of its divisors is an integer number (21885633).

Almost surely, 2^1221715710 is an apocalyptic number.

1221715710 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221715710, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1750850640).

1221715710 is an abundant number, since it is smaller than the sum of its proper divisors (2279985570).

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

1221715710 is an equidigital number, since it uses as much as digits as its factorization.

1221715710 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377 (or 334 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 27.

The square root of 1221715710 is about 34953.0500815022. The cubic root of 1221715710 is about 1069.0303936511.

Adding to 1221715710 its reverse (175171221), we get a palindrome (1396886931).

The spelling of 1221715710 in words is "one billion, two hundred twenty-one million, seven hundred fifteen thousand, seven hundred ten".