20969970 has 64 divisors (see below), whose sum is σ = 58496256. Its totient is φ = 4711680.

The previous prime is 20969953. The next prime is 20969989. The reversal of 20969970 is 7996902.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11992 + ... + 13628.

It is an arithmetic number, because the mean of its divisors is an integer number (914004).

Almost surely, 2^20969970 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20969970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29248128).

20969970 is an abundant number, since it is smaller than the sum of its proper divisors (37526286).

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

20969970 is a wasteful number, since it uses less digits than its factorization.

20969970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715.

The product of its (nonzero) digits is 61236, while the sum is 42.

The square root of 20969970 is about 4579.2979811320. The cubic root of 20969970 is about 275.7608461834.

The spelling of 20969970 in words is "twenty million, nine hundred sixty-nine thousand, nine hundred seventy".