2154978540 has 576 divisors, whose sum is σ = 8258342400. Its totient is φ = 463034880.

The previous prime is 2154978523. The next prime is 2154978557. The reversal of 2154978540 is 458794512.

2154978540 is a `hidden beast` number, since 2 + 15 + 4 + 97 + 8 + 540 = 666.

It is an interprime number because it is at equal distance from previous prime (2154978523) and next prime (2154978557).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 36525031 + ... + 36525089.

It is an arithmetic number, because the mean of its divisors is an integer number (14337400).

Almost surely, 2^2154978540 is an apocalyptic number.

2154978540 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 2154978540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4129171200).

2154978540 is an abundant number, since it is smaller than the sum of its proper divisors (6103363860).

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

2154978540 is a wasteful number, since it uses less digits than its factorization.

2154978540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The square root of 2154978540 is about 46421.7464126459. The cubic root of 2154978540 is about 1291.6583323685.

The spelling of 2154978540 in words is "two billion, one hundred fifty-four million, nine hundred seventy-eight thousand, five hundred forty".