1650401261 has 2 divisors, whose sum is σ = 1650401262. Its totient is φ = 1650401260.

The previous prime is 1650401257. The next prime is 1650401267. The reversal of 1650401261 is 1621040561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1508934025 + 141467236 = 38845^2 + 11894^2 .

It is a cyclic number.

It is not a de Polignac number, because 1650401261 - 2² = 1650401257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1650401261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1650401267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 825200630 + 825200631.

It is an arithmetic number, because the mean of its divisors is an integer number (825200631).

Almost surely, 2^1650401261 is an apocalyptic number.

It is an amenable number.

1650401261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1650401261 is an equidigital number, since it uses as much as digits as its factorization.

1650401261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 1650401261 is about 40625.1309044045. The cubic root of 1650401261 is about 1181.7615318714.

The spelling of 1650401261 in words is "one billion, six hundred fifty million, four hundred one thousand, two hundred sixty-one".