20670780 has 48 divisors (see below), whose sum is σ = 62332704. Its totient is φ = 5088000.

The previous prime is 20670763. The next prime is 20670817. The reversal of 20670780 is 8707602.

It is a super-2 number, since 2×20670780² = 854562291616800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

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, 12471 + ... + 14030.

It is an arithmetic number, because the mean of its divisors is an integer number (1298598).

Almost surely, 2^20670780 is an apocalyptic number.

20670780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20670780 is an abundant number, since it is smaller than the sum of its proper divisors (41661924).

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

20670780 is a wasteful number, since it uses less digits than its factorization.

20670780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26526 (or 26524 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 20670780 is about 4546.5129495032. The cubic root of 20670780 is about 274.4430822829.

The spelling of 20670780 in words is "twenty million, six hundred seventy thousand, seven hundred eighty".