1978498540 has 24 divisors (see below), whose sum is σ = 4162813200. Its totient is φ = 789882048.

The previous prime is 1978498531. The next prime is 1978498549. The reversal of 1978498540 is 458948791.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1978498531) and next prime (1978498549).

It is not an unprimeable number, because it can be changed into a prime (1978498549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84115 + ... + 105034.

It is an arithmetic number, because the mean of its divisors is an integer number (173450550).

Almost surely, 2^1978498540 is an apocalyptic number.

1978498540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1978498540 is an abundant number, since it is smaller than the sum of its proper divisors (2184314660).

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

1978498540 is a wasteful number, since it uses less digits than its factorization.

1978498540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189681 (or 189679 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 55.

The square root of 1978498540 is about 44480.3163208177. The cubic root of 1978498540 is about 1255.3897489503.

The spelling of 1978498540 in words is "one billion, nine hundred seventy-eight million, four hundred ninety-eight thousand, five hundred forty".