623851681 has 6 divisors (see below), whose sum is σ = 658414482. Its totient is φ = 591017040.

The previous prime is 623851639. The next prime is 623851699. The reversal of 623851681 is 186158326.

It can be written as a sum of positive squares in only one way, i.e., 318301281 + 305550400 = 17841^2 + 17480^2 .

It is not a de Polignac number, because 623851681 - 2¹³ = 623843489 is a prime.

It is a super-2 number, since 2×623851681² = 778381839773051522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (623851621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 863700 + ... + 864421.

It is an arithmetic number, because the mean of its divisors is an integer number (109735747).

Almost surely, 2^623851681 is an apocalyptic number.

It is an amenable number.

623851681 is a deficient number, since it is larger than the sum of its proper divisors (34562801).

623851681 is a wasteful number, since it uses less digits than its factorization.

623851681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1728159 (or 1728140 counting only the distinct ones).

The product of its digits is 69120, while the sum is 40.

The square root of 623851681 is about 24977.0230612057. The cubic root of 623851681 is about 854.4640262243.

The spelling of 623851681 in words is "six hundred twenty-three million, eight hundred fifty-one thousand, six hundred eighty-one".