21150401840 has 20 divisors (see below), whose sum is σ = 49174684464. Its totient is φ = 8460160704.

The previous prime is 21150401807. The next prime is 21150401843. The reversal of 21150401840 is 4810405112.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (21150401843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132189932 + ... + 132190091.

Almost surely, 2^21150401840 is an apocalyptic number.

21150401840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21150401840 is an abundant number, since it is smaller than the sum of its proper divisors (28024282624).

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

21150401840 is a wasteful number, since it uses less digits than its factorization.

21150401840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264380036 (or 264380030 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

Adding to 21150401840 its reverse (4810405112), we get a palindrome (25960806952).

The spelling of 21150401840 in words is "twenty-one billion, one hundred fifty million, four hundred one thousand, eight hundred forty".