20720700 has 432 divisors, whose sum is σ = 90994176. Its totient is φ = 3801600.

The previous prime is 20720681. The next prime is 20720717. The reversal of 20720700 is 702702.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 900889 + ... + 900911.

Almost surely, 2^20720700 is an apocalyptic number.

20720700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20720700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45497088).

20720700 is an abundant number, since it is smaller than the sum of its proper divisors (70273476).

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

20720700 is a wasteful number, since it uses less digits than its factorization.

20720700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 18.

The square root of 20720700 is about 4551.9995606327. Note that the first 3 decimals coincide. The cubic root of 20720700 is about 274.6638316493.

It can be divided in two parts, 207 and 20700, that multiplied together give a square (4284900 = 2070²).

The spelling of 20720700 in words is "twenty million, seven hundred twenty thousand, seven hundred".