20977164 has 96 divisors (see below), whose sum is σ = 59709440. Its totient is φ = 6329664.

The previous prime is 20977157. The next prime is 20977169. The reversal of 20977164 is 46177902.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (20977169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 93957 + ... + 94179.

Almost surely, 2^20977164 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20977164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29854720).

20977164 is an abundant number, since it is smaller than the sum of its proper divisors (38732276).

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

20977164 is a wasteful number, since it uses less digits than its factorization.

20977164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316 (or 308 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 20977164 is about 4580.0834053541. The cubic root of 20977164 is about 275.7923769344.

It can be divided in two parts, 2097 and 7164, that added together give a cube (9261 = 21³).

The spelling of 20977164 in words is "twenty million, nine hundred seventy-seven thousand, one hundred sixty-four".