28145348637961 has 9 divisors (see below), whose sum is σ = 28757181825799. Its totient is φ = 27546267392824.

The previous prime is 28145348637949. The next prime is 28145348638007. The reversal of 28145348637961 is 16973684354182.

The square root of 28145348637961 is 5305219.

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., 1000790156025 + 27144558481936 = 1000395^2 + 5210044^2 .

It is not a de Polignac number, because 28145348637961 - 2¹⁵ = 28145348605193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28145348637911) 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, 249288855 + ... + 249401731.

Almost surely, 2^{28145348637961} is an apocalyptic number.

28145348637961 is the 5305219-th square number.

28145348637961 is the 2652610-th centered octagonal number.

It is an amenable number.

28145348637961 is a deficient number, since it is larger than the sum of its proper divisors (611833187838).

28145348637961 is an frugal number, since it uses more digits than its factorization.

28145348637961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225848 (or 112924 counting only the distinct ones).

The product of its digits is 209018880, while the sum is 67.

The spelling of 28145348637961 in words is "twenty-eight trillion, one hundred forty-five billion, three hundred forty-eight million, six hundred thirty-seven thousand, nine hundred sixty-one".