65721654 has 24 divisors (see below), whose sum is σ = 143002080. Its totient is φ = 21814128.

The previous prime is 65721653. The next prime is 65721661. The reversal of 65721654 is 45612756.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65721653) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3337 + ... + 11940.

It is an arithmetic number, because the mean of its divisors is an integer number (5958420).

Almost surely, 2^65721654 is an apocalyptic number.

65721654 is an abundant number, since it is smaller than the sum of its proper divisors (77280426).

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

65721654 is a wasteful number, since it uses less digits than its factorization.

65721654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15524 (or 15521 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 65721654 is about 8106.8892924475. The cubic root of 65721654 is about 403.5550889163. Note that the first 3 decimals are identical.

The spelling of 65721654 in words is "sixty-five million, seven hundred twenty-one thousand, six hundred fifty-four".