685151235540 has 36 divisors (see below), whose sum is σ = 2078292081684. Its totient is φ = 182706996096.

The previous prime is 685151235523. The next prime is 685151235541. The reversal of 685151235540 is 45532151586.

685151235540 is a `hidden beast` number, since 6 + 8 + 51 + 51 + 2 + 3 + 5 + 540 = 666.

685151235540 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 356595288336 + 328555947204 = 597156^2 + 573198^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685151235541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1903197697 + ... + 1903198056.

Almost surely, 2^685151235540 is an apocalyptic number.

685151235540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

685151235540 is an abundant number, since it is smaller than the sum of its proper divisors (1393140846144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

685151235540 is a wasteful number, since it uses less digits than its factorization.

685151235540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3806395768 (or 3806395763 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 45.

The spelling of 685151235540 in words is "six hundred eighty-five billion, one hundred fifty-one million, two hundred thirty-five thousand, five hundred forty".