21727240626 has 288 divisors, whose sum is σ = 60022477440. Its totient is φ = 5201344512.

The previous prime is 21727240607. The next prime is 21727240637. The reversal of 21727240626 is 62604272712.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 24494755 + ... + 24495641.

It is an arithmetic number, because the mean of its divisors is an integer number (208411380).

Almost surely, 2^21727240626 is an apocalyptic number.

21727240626 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21727240626, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30011238720).

21727240626 is an abundant number, since it is smaller than the sum of its proper divisors (38295236814).

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

21727240626 is a wasteful number, since it uses less digits than its factorization.

21727240626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978 (or 958 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 39.

The spelling of 21727240626 in words is "twenty-one billion, seven hundred twenty-seven million, two hundred forty thousand, six hundred twenty-six".