21619691520 has 416 divisors, whose sum is σ = 83735347968. Its totient is φ = 4649385984.

The previous prime is 21619691507. The next prime is 21619691531. The reversal of 21619691520 is 2519691612.

It is a super-2 number, since 2×21619691520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7309882 + ... + 7312838.

Almost surely, 2^21619691520 is an apocalyptic number.

21619691520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21619691520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41867673984).

21619691520 is an abundant number, since it is smaller than the sum of its proper divisors (62115656448).

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

21619691520 is a wasteful number, since it uses less digits than its factorization.

21619691520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3013 (or 2991 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 42.

The spelling of 21619691520 in words is "twenty-one billion, six hundred nineteen million, six hundred ninety-one thousand, five hundred twenty".