651381990 has 48 divisors (see below), whose sum is σ = 1818556272. Its totient is φ = 148886976.

The previous prime is 651381967. The next prime is 651382033. The reversal of 651381990 is 99183156.

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

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 23 ways as a sum of consecutive naturals, for example, 220089 + ... + 223028.

It is an arithmetic number, because the mean of its divisors is an integer number (37886589).

Almost surely, 2^651381990 is an apocalyptic number.

651381990 is an abundant number, since it is smaller than the sum of its proper divisors (1167174282).

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

651381990 is a wasteful number, since it uses less digits than its factorization.

651381990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443141 (or 443134 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 42.

The square root of 651381990 is about 25522.1862308071. The cubic root of 651381990 is about 866.8525855244.

The spelling of 651381990 in words is "six hundred fifty-one million, three hundred eighty-one thousand, nine hundred ninety".