2551021155540 has 480 divisors, whose sum is σ = 9542094274944. Its totient is φ = 562334192640.

The previous prime is 2551021155521. The next prime is 2551021155559. The reversal of 2551021155540 is 455511201552.

2551021155540 is a `hidden beast` number, since 2 + 5 + 5 + 102 + 1 + 1 + 5 + 5 + 540 = 666.

It is an interprime number because it is at equal distance from previous prime (2551021155521) and next prime (2551021155559).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2551021155495 and 2551021155504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 15439042 + ... + 15603398.

Almost surely, 2^{2551021155540} is an apocalyptic number.

2551021155540 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 2551021155540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4771047137472).

2551021155540 is an abundant number, since it is smaller than the sum of its proper divisors (6991073119404).

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

2551021155540 is a wasteful number, since it uses less digits than its factorization.

2551021155540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164469 (or 164458 counting only the distinct ones).

The product of its (nonzero) digits is 50000, while the sum is 36.

The spelling of 2551021155540 in words is "two trillion, five hundred fifty-one billion, twenty-one million, one hundred fifty-five thousand, five hundred forty".