2456985781 has 8 divisors (see below), whose sum is σ = 2487222360. Its totient is φ = 2426898432.

The previous prime is 2456985761. The next prime is 2456985799. The reversal of 2456985781 is 1875896542.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 970883281 + 1486102500 = 31159^2 + 38550^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2456985781 - 2¹⁵ = 2456953013 is a prime.

It is a super-2 number, since 2×2456985781² = 12073558256072359922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2456985701) 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, 3996 + ... + 70213.

It is an arithmetic number, because the mean of its divisors is an integer number (310902795).

Almost surely, 2^2456985781 is an apocalyptic number.

It is an amenable number.

2456985781 is a deficient number, since it is larger than the sum of its proper divisors (30236579).

2456985781 is a wasteful number, since it uses less digits than its factorization.

2456985781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74615.

The product of its digits is 4838400, while the sum is 55.

The square root of 2456985781 is about 49567.9914965293. The cubic root of 2456985781 is about 1349.3798305565.

The spelling of 2456985781 in words is "two billion, four hundred fifty-six million, nine hundred eighty-five thousand, seven hundred eighty-one".