649521726 has 64 divisors (see below), whose sum is σ = 1582694400. Its totient is φ = 173568096.

The previous prime is 649521709. The next prime is 649521749. The reversal of 649521726 is 627125946.

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

It is a congruent 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, 57891 + ... + 68193.

It is an arithmetic number, because the mean of its divisors is an integer number (24729600).

Almost surely, 2^649521726 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649521726, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (791347200).

649521726 is an abundant number, since it is smaller than the sum of its proper divisors (933172674).

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

649521726 is a wasteful number, since it uses less digits than its factorization.

649521726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10413.

The product of its digits is 181440, while the sum is 42.

The square root of 649521726 is about 25485.7161170723. The cubic root of 649521726 is about 866.0265918547.

The spelling of 649521726 in words is "six hundred forty-nine million, five hundred twenty-one thousand, seven hundred twenty-six".