20687340 has 48 divisors (see below), whose sum is σ = 58288608. Its totient is φ = 5481984.

The previous prime is 20687339. The next prime is 20687363. The reversal of 20687340 is 4378602.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20687298 and 20687307.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9384 + ... + 11376.

It is an arithmetic number, because the mean of its divisors is an integer number (1214346).

Almost surely, 2^20687340 is an apocalyptic number.

20687340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20687340 is an abundant number, since it is smaller than the sum of its proper divisors (37601268).

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

20687340 is a wasteful number, since it uses less digits than its factorization.

20687340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2178 (or 2176 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 20687340 is about 4548.3337608403. Note that the first 3 decimals coincide. The cubic root of 20687340 is about 274.5163509956.

The spelling of 20687340 in words is "twenty million, six hundred eighty-seven thousand, three hundred forty".