2151421440 has 240 divisors, whose sum is σ = 8002135152. Its totient is φ = 491667456.

The previous prime is 2151421429. The next prime is 2151421453. The reversal of 2151421440 is 441241512.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×2151421440² = 9257228424983347200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 2151421440.

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, 373462 + ... + 379178.

Almost surely, 2^2151421440 is an apocalyptic number.

2151421440 is a gapful number since it is divisible by the number (20) 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 2151421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4001067576).

2151421440 is an abundant number, since it is smaller than the sum of its proper divisors (5850713712).

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

2151421440 is an equidigital number, since it uses as much as digits as its factorization.

2151421440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5757 (or 5734 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 2151421440 is about 46383.4177265971. The cubic root of 2151421440 is about 1290.9472520985.

Adding to 2151421440 its reverse (441241512), we get a palindrome (2592662952).

The spelling of 2151421440 in words is "two billion, one hundred fifty-one million, four hundred twenty-one thousand, four hundred forty".