1991542480 has 20 divisors (see below), whose sum is σ = 4630336452. Its totient is φ = 796616960.

The previous prime is 1991542453. The next prime is 1991542507. The reversal of 1991542480 is 842451991.

It is an interprime number because it is at equal distance from previous prime (1991542453) and next prime (1991542507).

It can be written as a sum of positive squares in 2 ways, for example, as 1407450256 + 584092224 = 37516^2 + 24168^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12447061 + ... + 12447220.

Almost surely, 2^1991542480 is an apocalyptic number.

1991542480 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1991542480 is an abundant number, since it is smaller than the sum of its proper divisors (2638793972).

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

1991542480 is a wasteful number, since it uses less digits than its factorization.

1991542480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24894294 (or 24894288 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 1991542480 is about 44626.7014241474. The cubic root of 1991542480 is about 1258.1425727033.

The spelling of 1991542480 in words is "one billion, nine hundred ninety-one million, five hundred forty-two thousand, four hundred eighty".