61921216770 has 64 divisors (see below), whose sum is σ = 170779504896. Its totient is φ = 14075216640.

The previous prime is 61921216717. The next prime is 61921216781. The reversal of 61921216770 is 7761212916.

It is a happy number.

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

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, 776529 + ... + 852548.

It is an arithmetic number, because the mean of its divisors is an integer number (2668429764).

Almost surely, 2^61921216770 is an apocalyptic number.

61921216770 is an abundant number, since it is smaller than the sum of its proper divisors (108858288126).

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

61921216770 is a wasteful number, since it uses less digits than its factorization.

61921216770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1629275.

The product of its (nonzero) digits is 63504, while the sum is 42.

The spelling of 61921216770 in words is "sixty-one billion, nine hundred twenty-one million, two hundred sixteen thousand, seven hundred seventy".