21000131554 has 16 divisors (see below), whose sum is σ = 32874672960. Its totient is φ = 10042043440.

The previous prime is 21000131519. The next prime is 21000131563. The reversal of 21000131554 is 45513100012.

It is a happy 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, 316617 + ... + 377155.

It is an arithmetic number, because the mean of its divisors is an integer number (2054667060).

Almost surely, 2^21000131554 is an apocalyptic number.

21000131554 is a deficient number, since it is larger than the sum of its proper divisors (11874541406).

21000131554 is a wasteful number, since it uses less digits than its factorization.

21000131554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68105.

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 21000131554 its reverse (45513100012), we get a palindrome (66513231566).

The spelling of 21000131554 in words is "twenty-one billion, one hundred thirty-one thousand, five hundred fifty-four".