101820342649 has 3 divisors (see below), whose sum is σ = 101820661743. Its totient is φ = 101820023556.

The previous prime is 101820342647. The next prime is 101820342697. The reversal of 101820342649 is 946243028101.

The square root of 101820342649 is 319093.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 97715634025 + 4104708624 = 312595^2 + 64068^2 .

It is not a de Polignac number, because 101820342649 - 2¹ = 101820342647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101820342647) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 159547 + ... + 478639.

It is an arithmetic number, because the mean of its divisors is an integer number (33940220581).

Almost surely, 2^101820342649 is an apocalyptic number.

101820342649 is the 319093-rd square number.

101820342649 is the 159547-th centered octagonal number.

It is an amenable number.

101820342649 is a deficient number, since it is larger than the sum of its proper divisors (319094).

101820342649 is an frugal number, since it uses more digits than its factorization.

101820342649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 638186 (or 319093 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The spelling of 101820342649 in words is "one hundred one billion, eight hundred twenty million, three hundred forty-two thousand, six hundred forty-nine".