2489991681 has 8 divisors (see below), whose sum is σ = 3325515424. Its totient is φ = 1657231200.

The previous prime is 2489991659. The next prime is 2489991737. The reversal of 2489991681 is 1861999842.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2489991681 - 2⁹ = 2489991169 is a prime.

It is a super-2 number, since 2×2489991681² = 12400117142898411522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2489991611) 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, 688711 + ... + 692316.

It is an arithmetic number, because the mean of its divisors is an integer number (415689428).

Almost surely, 2^2489991681 is an apocalyptic number.

It is an amenable number.

2489991681 is a deficient number, since it is larger than the sum of its proper divisors (835523743).

2489991681 is a wasteful number, since it uses less digits than its factorization.

2489991681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1381631.

The product of its digits is 2239488, while the sum is 57.

The square root of 2489991681 is about 49899.8164425482. The cubic root of 2489991681 is about 1355.3952689157.

The spelling of 2489991681 in words is "two billion, four hundred eighty-nine million, nine hundred ninety-one thousand, six hundred eighty-one".