650521978 has 4 divisors (see below), whose sum is σ = 975782970. Its totient is φ = 325260988.

The previous prime is 650521973. The next prime is 650521999. The reversal of 650521978 is 879125056.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 554932249 + 95589729 = 23557^2 + 9777^2 .

It is a super-2 number, since 2×650521978² = 846357687722064968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (650521973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 162630493 + ... + 162630496.

Almost surely, 2^650521978 is an apocalyptic number.

650521978 is a deficient number, since it is larger than the sum of its proper divisors (325260992).

650521978 is a wasteful number, since it uses less digits than its factorization.

650521978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325260991.

The product of its (nonzero) digits is 151200, while the sum is 43.

The square root of 650521978 is about 25505.3323444334. The cubic root of 650521978 is about 866.4709190720.

The spelling of 650521978 in words is "six hundred fifty million, five hundred twenty-one thousand, nine hundred seventy-eight".