101640453721 has 3 divisors (see below), whose sum is σ = 101640772533. Its totient is φ = 101640134910.

The previous prime is 101640453671. The next prime is 101640453727. The reversal of 101640453721 is 127354046101.

The square root of 101640453721 is 318811.

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 is not a de Polignac number, because 101640453721 - 2²³ = 101632065113 is a prime.

It is a super-2 number, since 2×101640453721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101640453727) 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, 159406 + ... + 478216.

It is an arithmetic number, because the mean of its divisors is an integer number (33880257511).

Almost surely, 2^101640453721 is an apocalyptic number.

101640453721 is the 318811-st square number.

101640453721 is the 159406-th centered octagonal number.

It is an amenable number.

101640453721 is a deficient number, since it is larger than the sum of its proper divisors (318812).

101640453721 is an frugal number, since it uses more digits than its factorization.

101640453721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637622 (or 318811 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

Adding to 101640453721 its reverse (127354046101), we get a palindrome (228994499822).

The spelling of 101640453721 in words is "one hundred one billion, six hundred forty million, four hundred fifty-three thousand, seven hundred twenty-one".