3121421520 has 120 divisors (see below), whose sum is σ = 11256270624. Its totient is φ = 713465088.

The previous prime is 3121421519. The next prime is 3121421531. The reversal of 3121421520 is 251241213.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×3121421520² = 19486544611038220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120954 + ... + 144473.

Almost surely, 2^3121421520 is an apocalyptic number.

3121421520 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3121421520 is an abundant number, since it is smaller than the sum of its proper divisors (8134849104).

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

3121421520 is a wasteful number, since it uses less digits than its factorization.

3121421520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265457 (or 265444 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 3121421520 is about 55869.6833712166. The cubic root of 3121421520 is about 1461.4506005454.

Adding to 3121421520 its reverse (251241213), we get a palindrome (3372662733).

The spelling of 3121421520 in words is "three billion, one hundred twenty-one million, four hundred twenty-one thousand, five hundred twenty".