21311950 has 24 divisors (see below), whose sum is σ = 43245000. Its totient is φ = 7749600.

The previous prime is 21311933. The next prime is 21311951. The reversal of 21311950 is 5911312.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311951) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18825 + ... + 19924.

It is an arithmetic number, because the mean of its divisors is an integer number (1801875).

Almost surely, 2^21311950 is an apocalyptic number.

21311950 is an abundant number, since it is smaller than the sum of its proper divisors (21933050).

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

21311950 is a wasteful number, since it uses less digits than its factorization.

21311950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38772 (or 38767 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 21311950 is about 4616.4867594308. The cubic root of 21311950 is about 277.2518139170.

The spelling of 21311950 in words is "twenty-one million, three hundred eleven thousand, nine hundred fifty".