3121721460 has 288 divisors, whose sum is σ = 11610563328. Its totient is φ = 668067840.

The previous prime is 3121721459. The next prime is 3121721497. The reversal of 3121721460 is 641271213.

3121721460 is a `hidden beast` number, since 31 + 2 + 172 + 1 + 460 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 589384 + ... + 594656.

It is an arithmetic number, because the mean of its divisors is an integer number (40314456).

Almost surely, 2^3121721460 is an apocalyptic number.

3121721460 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3121721460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5805281664).

3121721460 is an abundant number, since it is smaller than the sum of its proper divisors (8488841868).

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

3121721460 is a wasteful number, since it uses less digits than its factorization.

3121721460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5335 (or 5330 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 3121721460 is about 55872.3675889970. The cubic root of 3121721460 is about 1461.4974097156.

Adding to 3121721460 its reverse (641271213), we get a palindrome (3762992673).

The spelling of 3121721460 in words is "three billion, one hundred twenty-one million, seven hundred twenty-one thousand, four hundred sixty".