681501437 has 4 divisors (see below), whose sum is σ = 681941820. Its totient is φ = 681061056.

The previous prime is 681501433. The next prime is 681501461. The reversal of 681501437 is 734105186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 158281561 + 523219876 = 12581^2 + 22874^2 .

It is a cyclic number.

It is not a de Polignac number, because 681501437 - 2² = 681501433 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681501397 and 681501406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681501433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 217862 + ... + 220967.

It is an arithmetic number, because the mean of its divisors is an integer number (170485455).

Almost surely, 2^681501437 is an apocalyptic number.

It is an amenable number.

681501437 is a deficient number, since it is larger than the sum of its proper divisors (440383).

681501437 is a wasteful number, since it uses less digits than its factorization.

681501437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440382.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 681501437 is about 26105.5824872765. The cubic root of 681501437 is about 880.0126707025.

The spelling of 681501437 in words is "six hundred eighty-one million, five hundred one thousand, four hundred thirty-seven".