20720070 has 128 divisors (see below), whose sum is σ = 66585600. Its totient is φ = 4478976.

The previous prime is 20720057. The next prime is 20720083. The reversal of 20720070 is 7002702.

It is an interprime number because it is at equal distance from previous prime (20720057) and next prime (20720083).

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 35622 + ... + 36198.

It is an arithmetic number, because the mean of its divisors is an integer number (520200).

Almost surely, 2^20720070 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20720070, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33292800).

20720070 is an abundant number, since it is smaller than the sum of its proper divisors (45865530).

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

20720070 is a wasteful number, since it uses less digits than its factorization.

20720070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619 (or 613 counting only the distinct ones).

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

The square root of 20720070 is about 4551.9303597485. The cubic root of 20720070 is about 274.6610479601.

Adding to 20720070 its reverse (7002702), we get a palindrome (27722772).

The spelling of 20720070 in words is "twenty million, seven hundred twenty thousand, seventy".