661650025 has 12 divisors (see below), whose sum is σ = 824984524. Its totient is φ = 526392000.

The previous prime is 661650001. The next prime is 661650037. The reversal of 661650025 is 520056166.

It can be written as a sum of positive squares in 6 ways, for example, as 96589584 + 565060441 = 9828^2 + 23771^2 .

It is not a de Polignac number, because 661650025 - 2¹³ = 661641833 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68586 + ... + 77635.

Almost surely, 2^661650025 is an apocalyptic number.

It is an amenable number.

661650025 is a deficient number, since it is larger than the sum of its proper divisors (163334499).

661650025 is a wasteful number, since it uses less digits than its factorization.

661650025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146412 (or 146407 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 661650025 is about 25722.5586791050. The cubic root of 661650025 is about 871.3837252807.

The spelling of 661650025 in words is "six hundred sixty-one million, six hundred fifty thousand, twenty-five".