1978550280 has 128 divisors (see below), whose sum is σ = 7537363200. Its totient is φ = 452238336.

The previous prime is 1978550279. The next prime is 1978550281. The reversal of 1978550280 is 820558791.

It is a happy number.

1978550280 is a `hidden beast` number, since 1 + 9 + 78 + 550 + 28 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1978550279) and next prime (1978550281).

It is a super-2 number, since 2×1978550280² = 7829322420976156800, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (1978550281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 123297 + ... + 138416.

It is an arithmetic number, because the mean of its divisors is an integer number (58885650).

Almost surely, 2^1978550280 is an apocalyptic number.

1978550280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1978550280 is an abundant number, since it is smaller than the sum of its proper divisors (5558812920).

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

1978550280 is a wasteful number, since it uses less digits than its factorization.

1978550280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261740 (or 261730 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 45.

The square root of 1978550280 is about 44480.8979225914. The cubic root of 1978550280 is about 1255.4006921476.

The spelling of 1978550280 in words is "one billion, nine hundred seventy-eight million, five hundred fifty thousand, two hundred eighty".