626139540 has 72 divisors (see below), whose sum is σ = 2045396808. Its totient is φ = 154126080.

The previous prime is 626139523. The next prime is 626139541. The reversal of 626139540 is 45931626.

It is a happy number.

626139540 is a `hidden beast` number, since 6 + 261 + 395 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 20684304 + 605455236 = 4548^2 + 24606^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 626139495 and 626139504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (626139541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 131451 + ... + 136130.

It is an arithmetic number, because the mean of its divisors is an integer number (28408289).

Almost surely, 2^626139540 is an apocalyptic number.

626139540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

626139540 is an abundant number, since it is smaller than the sum of its proper divisors (1419257268).

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

626139540 is a wasteful number, since it uses less digits than its factorization.

626139540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267609 (or 267604 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 626139540 is about 25022.7804210483. The cubic root of 626139540 is about 855.5072807853.

The spelling of 626139540 in words is "six hundred twenty-six million, one hundred thirty-nine thousand, five hundred forty".