684420090 has 64 divisors (see below), whose sum is σ = 1732890240. Its totient is φ = 172523520.

The previous prime is 684420089. The next prime is 684420091. The reversal of 684420090 is 90024486.

It is an interprime number because it is at equal distance from previous prime (684420089) and next prime (684420091).

It is not an unprimeable number, because it can be changed into a prime (684420091) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 327850 + ... + 329930.

It is an arithmetic number, because the mean of its divisors is an integer number (27076410).

Almost surely, 2^684420090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684420090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (866445120).

684420090 is an abundant number, since it is smaller than the sum of its proper divisors (1048470150).

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

684420090 is a wasteful number, since it uses less digits than its factorization.

684420090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2687.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 684420090 is about 26161.4236997913. The cubic root of 684420090 is about 881.2671526263.

The spelling of 684420090 in words is "six hundred eighty-four million, four hundred twenty thousand, ninety".