1981407578 has 16 divisors (see below), whose sum is σ = 3056539200. Its totient is φ = 962793216.

The previous prime is 1981407577. The next prime is 1981407583. The reversal of 1981407578 is 8757041891.

It is a super-3 number, since 3×1981407578³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1981407577) 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, 40775 + ... + 75002.

It is an arithmetic number, because the mean of its divisors is an integer number (191033700).

Almost surely, 2^1981407578 is an apocalyptic number.

1981407578 is a deficient number, since it is larger than the sum of its proper divisors (1075131622).

1981407578 is a wasteful number, since it uses less digits than its factorization.

1981407578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116021.

The product of its (nonzero) digits is 564480, while the sum is 50.

The square root of 1981407578 is about 44513.0045941633. The cubic root of 1981407578 is about 1256.0047250725.

The spelling of 1981407578 in words is "one billion, nine hundred eighty-one million, four hundred seven thousand, five hundred seventy-eight".