19965407401 has 9 divisors (see below), whose sum is σ = 20179466103. Its totient is φ = 19753600200.

The previous prime is 19965407387. The next prime is 19965407467. The reversal of 19965407401 is 10470456991.

The square root of 19965407401 is 141299.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 19182527001 + 782880400 = 138501^2 + 27980^2 .

It is not a de Polignac number, because 19965407401 - 2²³ = 19957018793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19965407201) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 14270500 + ... + 14271898.

Almost surely, 2^19965407401 is an apocalyptic number.

19965407401 is the 141299-th square number.

19965407401 is the 70650-th centered octagonal number.

It is an amenable number.

19965407401 is a deficient number, since it is larger than the sum of its proper divisors (214058702).

19965407401 is an frugal number, since it uses more digits than its factorization.

19965407401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3000 (or 1500 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 46.

The spelling of 19965407401 in words is "nineteen billion, nine hundred sixty-five million, four hundred seven thousand, four hundred one".