21377537540500 has 24 divisors (see below), whose sum is σ = 46688541989544. Its totient is φ = 8551015016000.

The previous prime is 21377537540467. The next prime is 21377537540521. The reversal of 21377537540500 is 504573577312.

It can be written as a sum of positive squares in 4 ways, for example, as 2143190593296 + 19234346947204 = 1463964^2 + 4385698^2 .

It is a super-2 number, since 2×21377537540500² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21377537041 + ... + 21377538040.

It is an arithmetic number, because the mean of its divisors is an integer number (1945355916231).

Almost surely, 2^{21377537540500} is an apocalyptic number.

21377537540500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21377537540500 is an abundant number, since it is smaller than the sum of its proper divisors (25311004449044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21377537540500 is a wasteful number, since it uses less digits than its factorization.

21377537540500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42755075100 (or 42755075088 counting only the distinct ones).

The product of its (nonzero) digits is 3087000, while the sum is 49.

The spelling of 21377537540500 in words is "twenty-one trillion, three hundred seventy-seven billion, five hundred thirty-seven million, five hundred forty thousand, five hundred".